Methods and apparatus for fast and energy-efficient link recovery in visible light communication (vlc) system

FIELD: physics, communications.

SUBSTANCE: invention relates to communication engineering and can be used in optical communication systems. To this end, a visible light communication (VLC) device for use in a VLC system is provided. The VLC device detects a trigger condition indicating a breakdown of a VLC link associated with first allocated resources used to communicate with a second VLC device. In response to the detection, the VLC device terminates on the first allocated resources transmission of data to the second VLC device and transmits a fast link recovery (FLR) signal using the first allocated resources. The VLC device receives a fast link recovery response (FLR RSP) signal indicating that the second VLC device received the FLR signal and, in response, the VLC device resumes transmission of data to the second VLC device.

EFFECT: high communication reliability owing to rapid communication recovery.

19 cl, 2 tbl, 24 dwg

The technical FIELD TO WHICH the INVENTION RELATES.

The present application generally relates to communication systems based on visible light (VLC) and, more specifically, to the technical admission of fast reconnection (FLR) in the VLC system.

The LEVEL of TECHNOLOGY

A relationship based on the visible light (VLC) is a new technology optical wireless close range using visible light in optically transparent media. This technology provides access to several hundred THz unlicensed spectrum, resistance to electromagnetic interference and no interference with radio-frequency (RF) systems. The VLC technology also provides additional security by allowing the user to see the communication channel and communication that extends and complements existing infrastructure services (e.g., lighting, display, display, decoration, and so on) based on visible light. The VLC technology has been proposed for use in intelligent transportation systems (ITS) to transmit information about the security measures and other information between vehicles or between traffic lights and vehicles.

Link LOS (line of sight) between the two transceivers VLC is a big part of system applications VLC. Connection LOS preferably as visible light cannot pass through opaque barriers, such as a wall. However, temporary blocking, such as walking man, can cause frequent bursts of error frames in the VLC system. In addition, bad aiming of the VLC device may cause a decrease in signal quality or even the connection to fail. On the VLC system can also be affected by reducing the brightness of the light (for example, decreasing the brightness of the light infrastructure lighting devices). When the brightness of the light is reduced, a connection may suffer from reduced transmission time due to the use of pulse-width modulation, and/or loss of some information from a reduction in signal quality. Because VLC is highly directional, it is difficult to establish and maintain lines of communication between wireless devices that are mobile. In addition, associated with the orientation behavior VLC bothers to restore a connection that has been lost due to the movement or rotation of one of the devices in the connection.

DISCLOSURE of INVENTIONS

To overcome the disorder at least one system of the prior art proposes that the access point (AP) has provided the service of fast reconnection in the event of a link failure. AP allocates a dedicated mini-interval in the upward communication line (UL) for each user equipment (UE), also called a mobile node (MN) is whether the mobile device. After that, the MN transmits signals in a dedicated mini-interval in each frame up until the MN will not disconnect from the AP. However, in this approach, the MN always sends messages to a dedicated mini-interval for each frame. This can lead to a large number of official signals that you're wasting system resources. Approach with a dedicated mini-intervals can also consume a lot of battery power of the mobile node.

Another optical communication system, known as the Association for infrared data transmission (IrDA), uses access Protocol serial infrared communication channel (IrLAP) to provide point-to-point connection. System IrDA has reconnecting through functionality, called reconnection, and uses a CRC for error detection. To cope with the distortion or violation signal, IrLAP uses the sequential exchange of information with evidence. If a frame is corrupted by noise CRC highlight the error, and the frame is discarded. The IrLAP Protocol implements the strategy of automatic repeat request with the options of using stop and wait, go back to N and schemes selective retransmission failure. This strategy allows the level IrLAP to provide accurate, reliable connection with a higher level the mi.

However, the method used in IrDA, does not consider how to support different requirements of working time of mobile nodes from the battery. Some devices VLC (for example, infrastructure lighting devices) use AC (AC), and there is no need to consider the battery life. However, for mobile nodes, the battery life is an important factor. However, the approach reconnection IrDA does not take into account techniques for power management for longer battery life. In addition, because a reduction in the brightness of the light can affect the conditions of connection, reconnection must consider the factor of decreasing the brightness. However, the IrDA Protocol does not consider how to support decrease the brightness of the light.

Therefore, in engineering there is a need for an improved system VLC, which is less susceptible to breakage, due to a temporary blockage, dims, bad aiming and moving. In particular there is a need in the VLC system, which provides fast reconnection after the break and in point-to-point connections and the connections point - to-multi points.

The first communication device based on the visible light (VLC) is intended for use in the system of VLC. The first VLC device contains a control unit receiving the transmission DL the control transmission and reception of data; and the control unit connection detection triggering condition indicating a failure of the connection VLC corresponding to the first selected resources used for communication with the second VLC device, in response to detection of completion of data transmission to the first allocated resources to the second VLC device, signal transfer fast reconnection (FLR), using the first allocated resources, receiving the response signal fast reconnection (FLR RSP), indicating that the second VLC device took FLR signal, and resume data transmission to the second VLC device in response to receiving the signal FLR RSP.

In one embodiment of the present disclosure, the first VLC device is the access point of the network infrastructure.

In another embodiment of the present disclosure, the first VLC device is a mobile node that is used to gain access to the access point of the network infrastructure.

Provided a way to restore the connection for use in a communication system based on visible light (VLC). The method comprises the steps of: 1) detecting the first VLC device triggering conditions, indicating disconnection VLC corresponding to the first selected resources used for communication with the second VLC device; and 2) the termination of the first device on the om VLC data on the first resources allocated to the second VLC device. The method further comprises: 3) transmit the first VLC device signal fast reconnection (FLR), using the first allocated resources, and 4) receiving the first VLC device signal response fast reconnection (FLR RSP), indicating that the second VLC device received the signal FLR. The method also includes: 5) resuming the first VLC device data to the second VLC device in response to receiving the signal FLR RSP.

Before outlining the following detailed description of the invention, it may be useful to formulate definitions of certain words and phrases used throughout this patent document: the terms "include" and "include", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "appropriate" and "corresponding"as well as derivatives thereof, may mean to include, be logged in, to be in connection with, contain, be contained in, be connected to or with, be connected with or to to communicate with, cooperate with, interleave, be near, be close to, be connected with, or to, to have, to have property, etc. definitions of certain words and phrases are provided throughout this patent document, the technical people need to understand that in many, if not most cases, such ODA the division relate to the previous, as well as the future use of such defined words and phrases.

The present invention provides an improved system VLC, which is less susceptible to breakage, due to a temporary blockage, dims, bad aiming and moving. In particular, the present invention provides a system VLC, which provides fast reconnection after the break and in point-to-point connection and the connection point to many points.

BRIEF DESCRIPTION of DRAWINGS

Fig. 1 depicts an example communication system based on visible light (VLC), which supports bidirectional communication between the access point of the network infrastructure and a variety of mobile nodes according to the variant example of implementation of the disclosure;

Fig. 2 depicts an example communication system based on visible light (VLC), which supports equal bidirectional communication between multiple mobile nodes according to the variant example of implementation of the disclosure;

Fig. 3 depicts an example of the structure of the frame, which provides a fast reconnection in the VLC system according to the variant example of implementation of the disclosure;

Fig. 4 and 5 depict the filling to support vidnosti and decrease the brightness according to the variant example of implementation of the disclosure;

Fig. 6 depicts the rapid recovery of the connection is to the VLC system according to one variant of implementation of the disclosure;

Fig. 7 depicts an example of fast reconnection in the VLC system according to another variant of implementation of the disclosure;

Fig. 8 depicts an example of fast reconnection in the VLC system according to another variant of implementation of the disclosure;

Fig. 9 depicts an example of fast reconnection in the VLC system according to another variant of implementation of the disclosure;

Fig. 10 is a block diagram of the sequence of operations, which depicts an example message processing ACK / NACK in the fast reconnection according to one variant of implementation of the disclosure;

Fig. 11 is a block diagram of the sequence of operations, which depicts an example of running the fast reconnection according to one variant of implementation of the disclosure;

Fig. 12 and 13 depict the indicators of fast reconnection in the illustrative structures of frames according to different variants of implementation of the disclosure;

Fig. 14 depicts an example of fast reconnection in the VLC system according to one variant of implementation of the disclosure;

Fig. 15 depicts an example of rescheduling due to decrease brightness in the fast reconnection according to one variant of implementation of the disclosure;

Fig. 16 depicts PR the measures reconfiguration timer reconnection model, decrease the brightness and/or traffic type according to one variant of implementation of the disclosure;

Fig. 17 depicts an example of fast reconnection on the basis of the operating time of a battery according to one variant of implementation of the disclosure;

Fig. 18 and 19 depict an example of the fast reconnect with color bandwidths according to one variant of implementation of the disclosure;

Fig. 20 and 21 depict an example of the fast reconnect with many angles according to one variant of implementation of the disclosure;

Fig. 22 depicts an example of the fast reconnect with many angles according to another variant of implementation of the disclosure;

Fig. 23 depicts an example of passing a two-way flow of messages FLR according to the variant example of implementation of the disclosure;

Fig. 24 depicts an example of a VLC device according to the variant example of implementation of the present invention.

The IMPLEMENTATION of the INVENTION

Before outlining the following detailed description of the invention it may be useful to formulate definitions of certain words and phrases used throughout this patent document: the terms "include" and "include", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "appropriate" and "corresponding"as well as derivatives thereof, may mean to include, be logged in, in order to ahadiths in connection with, to contain, be contained in, be connected to or with, be connected with, or to, relationship with, cooperate with, interleave, be near, be close to, be connected with, or to, to have, to have property, etc. definitions of certain words and phrases are provided throughout this patent document, the technical people need to understand that in many, if not most instances, such definitions apply to prior, as well as the future use of such defined words and phrases.

Fig. 1-24, discussed below, and the various options for implementation that is used to describe the principles of the present disclosure in this patent document is provided only as an illustration and should not be construed in any way limiting the scope of disclosure. Specialists in the field of technology will be clear that the principles of the present disclosure can be implemented in any respectively arranged in the communication system based on visible light (VLC).

The present invention discloses methods and devices to support quick and efficient recovery connection for communication systems based on visible light (VLC), when the connection VLC influenced by many factors, such as the object, temporarily blocking the connection, not targeted guidance, changes the brightness of the light Il is a sudden large interference from external light sources.

Fig. 1 and 2 depict some applications for communication systems based on visible light (VLC). In Fig. 1 device infrastructure, such as access point (AP) 110, contains the VLC transceiver, which performs bidirectional communication with the transceivers VLC in two mobile nodes. In this example, the mobile node (MN) 120 is a mobile phone, and the mobile node (MN) 130 is a portable computer. AP 110 may be part of a local area network (LAN). Fig. 2 depicts equal bidirectional communication between transceivers in VLC MN 120 (mobile phone) and MN 130 (portable personal computer (PC)) and represents an equal bidirectional communication between the MN 120A and MN 120B (both mobile phones).

Fig. 24 shows the VLC device that is part of the MN or the AP 110 according to the variant example of implementation of the present invention. In Fig. 24 the VLC device includes unit 140 controls the connection, memory 142, block 141 admission control-transmission, the encoder 143, modulator 144, amplifier 145 transmitted signal, light emitting diode (LED) 146, the decoder 148, the demodulator 149, the amplifier 150 a received signal and a photodiode (PD) 147.

Unit 141 controls the reception-transfer processing data to send and receive data in accordance with VLC and controls the transmission and reception of data, and the overall operation of the device VLC. According to a variant example of implementation of this breath is retene unit 141 controls the reception-transmission delivers messages ACK or NACK (ACK or NACK), received from another device, VLC, block 140 control connection. Unit 141 controls the reception-transmission stops or re-starts the transmission and reception of data under the control unit 140 controls the connection during the execution of the process of fast reconnection. And during the process of quick recovery connection unit 141 controls the reception-transmission receives a message sent to another device VLC from block 140, the control connection, and transmits a message received from another device, VLC, unit 140 controls the connection.

Block 140 connection management controls the operation of the VLC device during fast reconnection, when running the fast reconnect satisfied, according to different variants of implementation of the present invention listed in the description.

Variant implementation of the present invention depicts a block 141 admission control-transfer unit 140, the control connection in the form of shared components, but it can be implemented in a single component according to another variant implementation.

In memory 142 stores programs for processing and control unit 140 controls the connection unit 141 controls the reception-transmission, control data, various updated stored data and so on, to the which are available in the working memory unit 140 controls the connection unit 141 controls the reception-transmission. In addition, in the memory 142 stores the start condition fast reconnection.

Fig. 3 depicts an example of the structure of the frame, which provides a fast reconnection in the VLC system according to the variant example of implementation of the disclosure. The frame structure is represented at the level of control the medium access (MAC). An example of a frame 210 upward communication provides a General interval for random access on a shared basis and the unit stops. An example of a frame 220 downlink has block start frame, which can be sequences of the preamble used for synchronization, and the block of the frame header, which contains information about the VLC system, such as sender ID, frame number, types of services, capabilities of the sender, planning, etc. Block header block may contain test sequence header (HCS) (not shown), which may be a sequence header CRC.

Each of the remaining parts of the frame 210 of the upward communication line and frame 220 downlink contains N intervals (interval 0 - interval N-1). Each interval may send one or multiple blocks packet data (PDU) MAC. For systems LAN N intervals in the frame 210 of the upward communication line and N intervals in the frame 220 downlink can support multiple mobile nodes. For ravnopra the telecommunication VLC N intervals can be defined. It should be noted that in one frame can have only one MAC PDU type or may be of mixed types of MAC PDU. The frame may end up with a block stop or block stop can be omitted.

PDU MAC can be of different types. One type PDU 230 MAC is used to transmit regular data and messages that are marked regular (Reg) flag 241. For this type PDU 230 MAC also contains a header 242 MAC PDU, which may contain the identifier of the destination type of the payload (data or MAC control message), etc. PDU 230 MAC also contains a test sequence 243 header (HCS), useful information 244 and a circular validation 245 redundant code (CRC). Useful information 244 may contain, for example, user data or MAC control message. CRC 245 is used in the VLC receiver to detect errors.

Another type of PDU 230 MAC is used to fill, which is indicated by a flag 241 PAD. PDU 230 MAC (i.e., the flag 251 PAD and filling 254) may be used for filling, for example, to achieve a fill factor of this model decrease the brightness or to provide a visual aid of light in the mouse. Fig. 4 and 5 depict an example of filling to ensure compliance with the fill factor for the mode on or off.

In one embodiment, the mobile node (MN) in the VLC system starts the process would be Trogo the connection is restored. During fast reconnection MN may decide to stop sending data. MN may repeatedly transmit the signal of the fast reconnect (FLR) on the AP using the same allocated resources (e.g., frequency and time intervals), which are used for data transmission. Thus, avoids the use of a dedicated mini-frame. If there is uplink (UL, that is, from the MN to the AP) a communication session (e.g., data transmission service, transmission service voice or messaging service, video etc) and downlink (DL, that is, from AP to MN) communication session (e.g., data transmission service, transmission service voice or messaging service, video etc), or if there is only downward communication session, the MN can wait for the stop data transmission or MN can optionally send signals FLR, if battery consumption is not important (for example, MN powered by external power supply). If the downward communication session is not present, then preferably the MN must send the FLR signal to the AP, even if the MN is not powered from an external power supply.

After receiving signal FLR AP forwards the response on the MN FLR. After the MN will answer FLR, MN and AP renew the relationship. If MN does not accept the answer FLR for the timer T_TIMEOUT that begins when a process is running FLR, MN may assume that the connection has been lost (not recoverable through the process FLR) and that the measures and counters, related FLR, can be reset, and the connection can be reset, or MN can disconnect and re-connect to AP. The timer T_TIMEOUT can be pre-set as a system parameter, or may be sent or communicated to the AP or MN via broadcast, unicast, etc.

The starting conditions of fast reconnection in a mobile node (MN) can be, for example: 1) the MN does not accept the signal ACK or NACK within the time specified by the timer, 2) MN receives a predetermined number (N) of successive NACK signals, 3) MN does not accept the ACK signal a predetermined number (N) time, 4) found consistent errors or 5) the quality of the channel is below a threshold. PDU MAC fill frames or fill PDU can be used for error detection or measurement of the quality of the channel. If the MAC PDU padding uses a special predefined or communicated to the model, so that the AP and the MN know the model, the receiver may compare the received and expected filling for error detection.

Fig. 6 depicts the fast reconnection in the VLC system according to one variant of implementation of the disclosure. Initially, the mobile node (MN) 120 and access point (AP) 110 are connected and communicate bidirectional manner (step 410), and ACK are transmitted and properly take the Xia (step 420). However, at some point, MN 120 does not take N times the ACK from the AP 110, where N is a preset threshold level. Alternatively, the MN 120 may take N times the NACK message from the AP 110. In the example N=3, so that the MN 120 determines that three (3) ACK from the AP 110 were not accepted (or accepted 3 messages NACK). This launch condition initiates the process of fast reconnection.

In response, the MN 120 stops the data transfer (step 425) and instead passes the AP 110 signal fast reconnection (FLR), using the same resources allocated in the frame of the uplink communication that MN 120 is typically used for data transfer on the AP 110. If there is a downward communication session (from AP to MN), such as a data service, the MN 120 terminates data transmission and waits, and can optionally pass signals FLR, where option can be performed, for example, on the basis of the status of the battery. For example, if MN 120 is powered from an external power supply, MN 120 may choose to send the signal FLR. Otherwise, the MN 120 may choose not to send. In the variant example of implementation, MN 120 transmits multiple signals FLR, including signals FLR 430A and 430B. When the AP 110 detects the signal FLR, AP 110 transmits a signal 440 response (RSP) on the MN FLR 120. After that, the MN 120 and the AP 110 resume bidirectional communication (step 450). As described above, the signals in block 460 are not required.

Fig. 7, the image is pressed fast reconnection in the VLC system according to another variant implementation of the disclosure. Initially, the mobile node (MN) 120 and access point (AP) 110 are connected and communicate bidirectional manner (step 510) and the ACK and NACK is transmitted and received properly (step 520). However, at some point, MN 120 does not accept ACK or NACK message from the AP 110 within a predetermined time =T1, where T1 is determined by the timer. This launch condition initiates the process of fast reconnection.

In response, the MN 120 stops the data transfer (step 525) and instead passes on the AP 110 signal fast reconnection (FLR), using the same resources allocated in the frame of the uplink communication that MN 120 is typically used for data transfer on the AP 110. If there is a service of data transmission on downlink (from the AP to MN), MN 120 terminates data transmission and waits, and can optionally pass signals FLR, where option can be performed, for example, on the basis of the status of the battery. For example, if MN 120 is powered from an external power supply, MN 120 may choose to send the signal FLR. Otherwise, the MN 120 may choose not to send. In the variant example of implementation, MN 120 transmits multiple signals FLR, including signals FLR 530A and 530B. When the AP 110 detects the signal FLR, AP 110 transmits a signal 540 response (RSP) on the MN FLR 120. After that, the MN 120 and the AP 110 resume bidirectional communication (step 550).

In another embodiment, the point DOS the UPA (AP) in the VLC system initiates the process of fast reconnection. During fast reconnection AP may stop sending data to the mobile node (MN). Then AP repeatedly sends a signal to the fast reconnect (FLR) on MN. AP holds resources provide uplink communication is allocated to the MN. After receiving signal FLR MN sends a response signal (RSP) FLR on the AP. After the AP receives the signal FLR RSP, communication resumes. If the AP does not accept the answer FLR for the timer T_TIMEOUT_AP that begins when a process is running FLR, AP can assume that the connection has been lost (not recoverable through the process FLR) and all timers and counters associated with the FLR process, can be reset, providing uplink communication held for MN, may be released, and the connection can be reset. The timer T_TIMEOUT_AP can be pre-set as a system parameter, or may be sent or communicated to the AP or MN via broadcast, unicast, etc

The starting conditions of fast reconnection in AP can be, for example: 1) the AP does not accept messages ACK or NACK from MN for some time T2 defined by the timer, 2) AP receives a predetermined number (N) of successive NACK messages, 3) found consistent errors in AP, 4) the quality of the channel is below a threshold or 5) AP does not accept messages ACK is t MN a predetermined number of times. Again, the MAC PDU fills or frames the filling can be used for error detection or measurement of the quality of the channel. If the MAC PDU padding uses a special pre-defined or communicated to the model, so that the AP and the MN know the model, the receiver may compare the received and expected filling for error detection.

Fig. 8 depicts the fast reconnection in the VLC system according to one variant of implementation of the disclosure. Initially, the mobile node (MN) 120 and access point (AP) 110 are connected and communicate bidirectional manner (step 610), and ACK are transmitted and properly received (step 620). However, at some point AP 110 does not accept from MN 120 ACK message N times, where N is a preset threshold level. In the example N=3, so that the AP 110 determines that three (3) ACK message from the MN 120 were not accepted. This launch condition initiates the process of fast reconnection.

In response, the AP 110 stops the data transfer, keeps providing uplink connection to the MN (step 625) and instead transmits a signal fast reconnection (FLR) to MN 120, using the same resources allocated in the frame of the downlink, which AP 110 is typically used for data transfer to MN 120. In the variant example of implementation of the AP 110 transmits a lot of FLR signals, including signals FLR 630A and 630B. To the GDS MN 120 detects the signal FLR, MN 120 transmits a signal 640 response (RSP) FLR on the AP 110. After that, the MN 120 and the AP 110 resume bidirectional communication (step 650).

Fig. 9 depicts the fast reconnection in the VLC system according to another variant implementation of the disclosure. Initially, the mobile node (MN) 120 and access point (AP) 110 are connected and communicate bidirectional manner (step 710), and ACK and NACK is transmitted and properly received (step 720). However, at some point AP 110 does not accept from MN 120 ACK or NACK within a predetermined time =T2, where T2 is determined by the timer. This launch condition initiates the process of fast reconnection.

In response, the AP 110 stops the data transfer, keeps providing uplink connection to the MN (step 725), and instead transmits a signal fast reconnection (FLR) to MN 120, using the same resources allocated in the frame of the uplink communication, which AP 110 is typically used for data transfer to MN 120. In the variant example of implementation of the AP 110 transmits a lot of FLR signals, including signals FLR 730A and 730B. When the MN 120 detects the signal FLR, MN 120 transmits a signal 740 of the response (RSP) FLR on the AP 110. After that, the MN 120 and the AP 110 resume bidirectional communication (step 750).

In one embodiment of the present disclosure if there is only the data service in the ascending line tie is (UL) and there is no data transmission on downlink (DL), the MN 120 sends a signal FLR on the AP 110. If there is only the data service on DL and there is no data transmission on UL, AP 110 sends a signal on the MN FLR 120 and MN 120 waits for a signal FLR. If the available data services and for DL and UL, and the AP 110 is powered by an external (e.g., AC) power source, AP 110 sends a signal on the MN FLR 120. If MN 120 operates from an external power source (not on battery), MN 120 can optionally pass a signal FLR on the AP 110.

Compared with the above-described technique of the prior art, which uses a dedicated mini-interval, the present invention has numerous advantages. MN 120 sends signals FLR not at all during the corresponding time interval, and only as needed when you are satisfied certain conditions. ACK and NACK used in normal communication Protocol, automatically serve as the ping signal, giving the AP 110 to know that the connection is active. This reduces battery consumption in MN 120. In addition, MN 120 stops sending data, if satisfied certain conditions. These conditions cannot be based on a single signal, which may not be accepted due to a bad connection in a single moment. Instead, the conditions can be based on some history that makes the method more flexible and reliable.

Another advantage of the image is to be placed is when the AP 110 sends signals on the MN FLR 120, MN 120 reduces battery consumption. As AP 110 infrastructure is often light apparatus, AP 110 usually has no problems with battery. In addition, the AP 110 actively repeatedly checks the connection with the MN 120, so that the reconnection can be fast, because it can capture the time effect of the sudden improvement of the connection (for example, elimination of the blocking object).

Fig. 10 is a flowchart of the sequence of operations depicting the processing of messages ACK / NACK in the fast reconnection according to one variant of implementation of the disclosure. Fig. 10 shows an example of a possible processing NACK and ACK or AP 110 or MN 120 or both. Initially, it is assumed that the MN 120 and the AP 110 is connected and working properly (step 810). As the reception of each frame, the receiving device (MN 120 or AP 110) verifies that the frame header is correct (step 820). If the frame header is not correct, the receiving device transmits a signal NACK1.

If the frame header is correct, the receiving device verifies that the MAC PDU header is correct (step 830). If the MAC PDU header is not correct, the receiving device transmits a signal NACK2. If the MAC PDU header is correct, the receiving device verifies that the entire MAC PDU is correct (E. the AP 840). If the entire MAC PDU is not correct, the receiving device transmits a signal NACK3. If the entire MAC PDU is correct, the receiving device transmits the ACK signal.

In some systems may only be the ACK signals and NACK signals can be omitted. In other systems can be limited NACK signals (for example, only NACK3). In other systems, the NACK signals can not be differentiated as NACK1, NACK2 and NACK3, as shown in Fig. 10, in this case, a NACK will be considered in the aggregate for all occasions NACK.

Since there are various reasons causing poor connection, leading to bursts of errors, the use of reconnection may be different for different cases. If an object is blocking the connection or is a bad move, can be used fast reconnection. However, to change the brightness of the light can be adjusted timers used in fast reconnection. For sudden large interference can be customised adaptation speed transmission, noise suppression and adaptation of power.

Fig. 11 is a flowchart of the sequence of operations depicting the operation of fast reconnection (FLR) in AP 110 according to one variant of implementation of the disclosure. It should be borne in mind that a similar operation FLR can be R alisova in MN 120. However, for simplicity, the following example assumes that the AP 110 is a device that initiates the operation FLR. Fig. 11 shows an example of the conditions that trigger the reconnection, and the triggering conditions adaptation speed transmission. For a system that transmits only the ACK message, the triggering conditions for the rapid restoration of the connection and adaptation in speed of transmission may vary. For a system with not distinguish NACK messages can also be different running conditions. Initially it is assumed that the MN 120 and the AP 110 is connected and working properly (step 910).

During an active session, the receiving device (AP 110) determines whether ACK or NACK is not taken during each period T1 of the timer (step 920). If ACK or NACK was taken during each time interval T1, the AP 110 also determines whether the message NACK1 or NACK2 taken C_N times in a row (step 930). If ACK or NACK has not been adopted in each period T1 of the timer, or if the message NACK1 or NACK2 was taken C_N times in a row, then AP 110 initiates the operation of fast reconnection (FLR). AP 110 stops the transmission of useful data on the MN 120 and repeatedly transmits the signal FLR. AP 110 continues to hold the resources for uplink communication is allocated to the MN 120 (step 940).

If MN 120 does not transmit the signal FLR RSP within the Ah some predetermined interval of time T3, the AP 110 is detached from the MN 120 (i.e., closes the connection, and redistributes resources) (step 970). If MN 120 transmits a signal FLR RSP within an interval of time T3, the AP 110 continues the data transfer (step 960).

If ACK or NACK was taken during each period T1 of the timer, and if the message NACK1 or NACK2 was not accepted C_N times in a row, then AP 110 determines whether the message received NACK3 C_N3 times in a row (step 950). If the message NACK3 was not accepted C_N3 times in a row, then AP 110 continues the data transfer (step 960). If the message NACK3 was taken C_N3 times in a row, then AP 110 initiates, for example, the adaptation process on the transmission rate (i.e., reduces the data rate or the procedure of adaptation of supply (process step 940).

Fig. 12 and 13 depict the indicators of fast reconnection in the illustrative structure of a frame according to different variants of implementation of the disclosure. In Fig. 12 signal fast reconnection (FLR) can be, for example, one-bit field (for example, FLR=1) in the frame header (FH), acting as the ping signal, if the target mobile device is indicated in the frame header. Alternatively, the signal fast reconnection (FLR) can be, for example, one-bit field (for example, FLR=1) in the header of the MAC PDU, acting as the ping signal, if the target mobile device is istwo specified in the MAC PDU header.

In another embodiment, the FLR signal can be designed as a message to the control of MAC. For example, the signal FLR can be reserved MAC control message (i.e. A message), in which one-bit field (FLR=1) indicates that this signal FLR. Alternatively, the message type control MAC (i.e., type a message) may be reserved for transmitting only messages FLR and may not contain useful information. Except in the case of the frame header, the FLR signal can be transmitted multiple times in one frame.

In Fig. 13 signal response fast reconnection (FLR RSP) may be, for example, one-bit field (for example, FLR RSP=1) in the frame header (FH), acting as the ping signal, if the target device is specified in the frame header. Alternatively, the signal FLR RSP may be, for example, one-bit field (for example, FLR RSP=1) in the header of the MAC PDU, acting as the ping signal, if the target device is listed in the MAC PDU header.

In another embodiment, the signal FLR RSP can be designed as a MAC control message. For example, the signal FLR RSP can be reserved MAC control message (i.e. A message), in which one-bit field (FLR=0) indicates that this signal FLR RSP. Alternatively, the MAC control message (i.e., type B messages) may be the dawn of envirofone to send only messages FLR RSP and may not contain useful information. Except in the case of the frame header, the FLR signal can be transmitted multiple times in one frame.

The FLR signal and the signal FLR RSP can also jointly coded with other fields in the frame (for example, other fields in FH, the MAC PDU header or other messages into useful information PDU). PDU fills or frames to decrease the brightness, or provide vidnosti can be reduced or removed to add a lot of messages FLR or FLR RSP. Manager AP can flexibly schedule the FLR signal, for example, optionally, in each frame, to make a quick recovery.

In preferred embodiments, the implementation of the present invention the configuration of the timer and the limits of counter NACK messages can be adaptive and can be changed, and not fixed. Timers can be set in different ways for different types of traffic in an active session or for different planning approaches for different traffic (e.g., priority, polling, and so on). For example, the timer for high-priority traffic may be less, while a timer for low-priority traffic can be longer. The timer may also be different for different models decrease the brightness for infrastructure or fill factors due VLC.

Fig. 14 depicts the fast reconnection in the VLC system according to gnome variant implementation of the disclosure. Initially, the mobile node (MN) 120 and access point (AP) 110 are connected and communicate bidirectional manner (step 1110), and ACK and NACK is transmitted and properly received (step 1120). However, at some point there is a reduction in brightness and/or can be adjusted timer (e.g., from T2 to T2') in AP 110 (step 1125). In response, the AP 110 may reallocate resources to the MS 120 and/or reschedule transfer to MN 120 (step 1130), and can be adapted according to the transmission speed by adjusting the speed of data transfer (step 1140). As a result, in the MN 120 because adjustments can happen packet loss. Thus, the AP 110 may receive the ACK and/or NACK from the MN 120 within a predetermined time = T2'. This launch condition initiates the process of fast reconnection.

In response, the AP 110 stops the data transfer, keeps providing the upward communication line (step 1145), and instead transmits a signal fast reconnection (FLR) to MN 120, using the same resources allocated in the frame of the uplink communication, which AP 110 is typically used for data transfer to MN 120. In the variant example of implementation of the AP 110 transmits a lot of FLR signals, including signals FLR 1150A and 1150B. When the MN 120 detects the signal FLR, MN 120 transmits a signal FLR RSP 1160 on the AP 110. After that, the MN 120 and the AP 110 resume bidirectional communication (the tap 1170).

Fig. 15 depicts reschedule due to the reduction of brightness in the fast reconnection according to one variant of implementation of the disclosure. Fig. 16 depicts an example of a reconfiguration timer reconnection model, decrease the brightness and/or traffic type according to one variant of implementation of the disclosure. In Fig. 15, the traffic with a higher priority, such as voice and interactive video, guaranteed from the point of view of the service and under them is given a greater bandwidth when you reschedule due to decrease brightness, as these types of traffic are intolerant to delays.

In Fig. 15, an example of a regular planning from the top depicts the transmission of voice information on MN1, data, interactive video for MN2 and non-guaranteed (BE) data to MN3, MN4 and MN5. Not guaranteed data more tolerant of delays than video or voice data.

When there is a reduction of brightness, the transmission rate can be reduced. Therefore, to transfer the same amount of information requires more transmission time. As MN1 and MN2 are intolerant of delays and require a large bandwidth (i.e., greater transmission time), less time will be available for other MN, so some mobile nodes may not be scheduled no resources. P is the iMER rescheduled due to the reduction of 1 brightness while gear for MN1 and MN2 increased, and the time of transmission of traffic data is not guaranteed reduced to MN3, MN4 and MN5.

However, the decrease in brightness can affect the transmission rate, and if the timer for reconnection is defined as the time interval (T1) time, not the number of retransmissions, then the timer should be adjusted. For example, if reducing the brightness makes the transfer less frequent, as shown in the example rescheduled due to reduction 2 brightness, then the timer should be increased in order to restore the connection, as in the case of MN3. In addition, some mobile nodes (e.g., MN5) may not be scheduled earlier if there has been a decrease in brightness.

In a preferred embodiment of the invention, the VLC device is able to notify other devices VLC on the status of the operation time of the battery. If conditions start the process FLR, the first VLC device may compare its own battery life with the battery life of the second VLC device, which communicates the first VLC device. If the battery life of the first VLC device is less then the first VLC device stops sending data and waits. If the battery life of the first VLC device more, the first VLC device stops sending data and initiates the process of fast reconnection (FLR).

Time BA is area AP, MN or any of the VLC device may be communicated to other devices VLC through signal transmission (e.g., specifically defined MAC management messages power management). All the above are ways of implementation can also be extended to peer-to-peer connection.

Fig. 17 depicts the operation of fast reconnection on the basis of the operating time of a battery according to one variant of implementation of the disclosure. In Fig. 17 device A VLC (MN or AP) communicates with device B VLC (MN or AP). Initially, the device A and device B are connected and communicate bidirectional manner (step 1315), and ACK are transmitted and properly received (step 1320).

Device A and device B also exchanged (periodically or pereodicheski) information about the status of the battery (step 1325). In the preferred embodiment, device A and device B uses the status of the battery as a parameter, to determine what the device sends signals FLR.

At some point, executed a launch condition that initiates the process of fast reconnection. For example, A device may not be take N consecutive ACK message (step 1330). Alternatively, the device B may not take N consecutive ACK message (step 1335). In other embodiments, in which the start condition may be the expiration of a timer or the reception of the NACK signals N times in a row. If the device does not accept any answer FLR for the timer T_TIMEOUT_DEVICE that begins when a process is running FLR, the device may assume that the connection has been lost (not recoverable through the process FLR), and all timers and counters associated with the FLR process, can be reset, providing uplink communication held for MN, may be released, and the connection can be reset. The timer T_TIMEOUT_DEVICE can be defined as a system parameter, or may be sent or communicated to the device via broadcast, unicast, etc.

In Fig. 13 it is assumed that the device A has a shorter battery life than device B. Thus, if a device does not accept N consecutive ACK from device B, device A stops sending data and waits for the device B will send signals FLR (step 1330). If device B does not accept N consecutive ACK message from the device A and the device B has a battery life of more than device A, the device B stops sending data (step 1335) and automatically starts transmitting signals FLR. In the variant example of implementation, the device B ultimately sends many signals FLR, including the FLR signal 1340A and signal FLR 1340B, using the same resources allocated for the connection, usually ispolzuemogo the data to device A. When the device detects A signal FLR, the device A transmits a signal 1350 response (RSP) FLR device B. the device A and device B resume bidirectional communication (step 1360).

One of the advantages of this alternative implementation is that device A and device B help each other from the point of view of spending time battery during fast reconnection. If one of the devices is powered from an external power source, and not from the battery, it is powered by an external power supply device is better suited for transmitting signals FLE. Thus, the device is powered from the battery reduces the battery consumption.

In another embodiment of the disclosure, when running operation fast reconnection, if the VLC device has a spare color bandwidth, some or all of the spare color bandwidth can be used to send signals to fast reconnection. Another VLC device then selects the color bandwidth for a quick answer reconnection to continue communication. The process is fast reconnection on the color bandwidths can be executed in parallel in multiple color bandwidths or sequentially (i.e. one bandwidth for d the natives).

Fig. 18 and 19 depict fast reconnect with color bandwidths according to one variant of implementation of the disclosure. In Fig. 19, A device able to communicate with device B, using one or more of the M color bandwidths. However, some color bandwidth (for example, color 1) may not be accepted, while the other color bandwidth accepted. In Fig. 18, the device is A VLC (MN or AP) communicates with device B VLC (MN or AP). Initially, the device A and device B are connected and communicate by two-color image on A (step 1420). At some point, activates the trigger condition that leads to the initiation of the fast reconnection. For example, the device A transmits a message 1425 data and message 1430 data and does not receive the ACK for none of these data messages.

In response to a trigger condition, the device A transmits one or more signals FLR on device B for all available color the bandwidth used by the device a and device B, including illustrative signal 1440 FLR. When the device B detects the signal FLR on, for example, the color bands P and Q bandwidth, device B responds by transmitting a signal 1450 response (RSP) FLR device on A common color bands of the x, P and Q bandwidth. The device then selects A color strip Q bandwidth (step 1455), and the device A and device B resume bidirectional communication on the colour bar Q bandwidth (step 1460).

One of the advantages of the above-mentioned variant implementation is that when a certain color there is strong interference, the VLC device quickly switch to the available color bandwidth, which may not be subjected to strong interference. This is a case of using the color (frequency) explode. If free many common color channels (from the point of view of the frequency and/or time)can be selected new color channels based on the algorithm of selection of channels, and the communication can be resumed from the same state on the new channel physical layer.

In another embodiment of the disclosure, when running the fast reconnection, if the devices are available other direction (angles) (for example, light multiple LEDs with different angles), some or all of the other angles can be used to send signals to the fast reconnect to reconnect. Then the VLC device selects one or multiple angles, which will get the answer fast reconnection to continue communication. The process of rapid recovery of the is placed on the other directions (angles) can be executed in parallel on multiple destinations or sequentially (i.e., one direction behind the other).

Different angles can also be used by combining the use of the separation time (for example, multiplexing time division (TDM)or the joint use of color bandwidths. Different angles can also be used simultaneously and to use all available color bandwidth or only some of the color bandwidth. To maximize the probability of finding good available compounds can be used all available angles and color bandwidth.

Different angles may vary with angle indicator. The angle indicator may be, for example, the field in the frame header, the header of the PDU, etc. If there is, for example, 8 angles for communication, for the field can be used three bits. This alternative implementation is also applicable to the case in which the device has many light-emitting diodes (LED), located in various places, for example one on the left side, another on the right side of the device.

Preferably, when there is strong interference or blocking from a certain angle, then the VLC device can quickly switch the connection to another angle, which is not experiencing strong interference or blocking. This is a case of using spatial diversity.

Fig. 20 I depict fast reconnect with multiple angles according to one variant of implementation of the disclosure. In Fig. 21, A device able to communicate with device B in the direction 1503, but cannot communicate in the direction 1502 because of the opaque object 1501. The device is A VLC (MN or AP) communicates with device B VLC (MN or AP). Initially, device A and device B are connected and communicate bi-directional manner in the X direction (step 1510). At some point you start condition, which leads to the initiation of fast reconnection. For example, the device A transmits a message 1520 data and message 1530 data and does not receive the ACK for none of these data messages.

In response to a trigger condition, the device A transmits one or more signals FLR device B in all directions, used by device a and device B, including illustrative signal 1540 FLR. When the device B detects the signal FLR, coming, for example, Y-direction, the device B responds by transmitting a signal 1550 response (RSP) FLR on the device in A direction Y. then, the device A selects the Y direction (step 1555), and the device A and device B resume bidirectional communication in the Y direction (step 1560).

In another embodiment, the disclosure signaling FLR may include a direction indicator signal if one or many directions available device is Wu for transmitting signals. For example, the first VLC device may indicate the direction index signal FLR, using N bits, if the device can transmit directions up to 2^N. The first VLC device sends many signals FLR, where each signal FLR contains the index of the direction for this signal FLR. When the second VLC device receives signals FLR, the second VLC device sends the received indicator(s) the direction of the FLR signal in the signal FLR RSP. When the first VLC device takes FLR RSP with the inserted indicator(s) direction signal, the first VLC device may select one or more of these areas on the basis of indications, such as the power of the received signal.

In addition, the second device may select which signal(s) FLR reply using the signal(s) FLR RSP. For example, the second VLC device may choose to answer the first signal FLR or, if the second VLC device measures the signal strength, choose to answer one or many of the strongest received signals FLR.

If the first VLC device receives the signal FLR RSP index(AMI) signal, and if the first VLC device measures how strong the signal FLR RSP, the first VLC device may consequently choose a new direction (for example, by selecting one or more best connection). Alternatively, the first VLC device may choose direction is, specified in the signal FLR RSP, which is taken first.

The signal fast reconnection and the response can be specified using the format command fast reconnection at the MAC level. For example, the fast reconnect should be formatted as shown in table 1 below. The FLR signal and the signal FLR RSP vary the first bit (bit 0) of the field FLR in the frame command fast reconnection. The device can indicate the direction index of the FLR signal by using bits 1-3 field FLR in the frame command. If the unit receives the signal FLR and should send a signal to the FLR RSP, the device repeats the received indication of the direction of the FLR signal by using bits 1-3 field FLR in the frame command. If the device has only one direction, it uses '000' as the index of the default direction.

If there is one, the frame identifier of the team assigned to the FLR signal, and the other frame identifier command, assigned to the signal FLR RSP, the bit '0' may be reserved, and field FLR can be accordingly adapted. Alternatively, it may be an indication that you've added the indication of the direction or not.

For example, a field FLR can be the following:

bit 0=0: indicates that this signal FLR;

bit 0=1: indicates that this signal FLR RSP;

bit 1=0: no direction index (implies that there is only one direction);

bit 1=1: the referral rate provided;

bits 2-4: have meaning only if bit 1=1; index direction signal FLR, if bit 0=0, or index direction of a received signal FLR, if bit 0=1;

bits 5-7: reserved.

Fig. 22 depicts the fast reconnect with many angles according to another variant implementation of the disclosure. The device is A VLC (MN or AP) communicates with device B VLC (MN or AP). Initially, device A and device B are connected and communicate bi-directional manner in the X direction (step 1610). At some point you start condition, which leads to the initiation of fast reconnection. For example, give the creation A sends a message 1620 data and message 1630 data and does not receive the ACK message for any of these data messages.

In response to a trigger condition, the device A transmits one or more signals FLR on device B according to the multitude of directions used by the device a and device B, including illustrative signal 1640 FLR. Each signal FLR contains the index direction. When the device B detects signals FLR, coming, for example, from multiple directions, the device B selects one or more signals FLR, who will be responsible (step 1645), and responds by transmitting a variety of signals, response (RSP) FLR, including illustrative response signal 1650 FLR on device A. Each signal FLR RSP contains the indices of the directions of the signals received FLR. The device then selects A new direction(I) transmission (TX) (step 1655) and the device A and device B resume bidirectional communication on a new direction(s) (step 1660).

As an extension of the option exercise above, the device B, which receives signals from FLR device A can also have multiple lines for transmitting signals FLR RSP. In response to the signal FLR device B can also specify the index of the direction signal FLR RSP, and the index(s) direction of received signals FLR. When device A receives the signal FLR RSP, the device A can specify a different signal FLR indexes direction of received signals FLR RSP to indicate to the device B, which areas are good on the I signal FLR RSP. Device B may then send signals FLR RSP in one or more selected directions, where the selection may be based on one or multiple factors (e.g., signal strength).

In addition, the device B, which receives signals FLR index directions specified in the FLR signals can choose which signal FLR to respond using signal FLR RSP. For example, device B may choose to answer the first signal FLR or may choose to respond to the strongest received signal FLR, if device B measures the signal strength.

Device A, which receives signals FLR RSP index directions specified in the signals FLR RSP can choose which signal FLR RSP to respond by transmitting another signal FLR, containing the indices of the directions of the signals received FLR RSP. For example, device A may choose to answer the first signal FLR RSP or may choose to respond to the strongest received signal FLR RSP, if a device measures the signal strength.

In the FLR signals and FLR RSP this indicator can be used to specify use of the signal. For example, indicator = 00 may indicate that the received signal is the first signal FLR. Indicator = 01 may indicate that the received signal is a signal FLR RSP. Indicator = 10 can indicate that the received signal is a signal FLR generated for the ETA on the received signal FLR RSP. The indicator may be in the FLR. Alternatively, it may be modified frame identifier command, to distinguish between different options FLR.

When the indicator indicates that the received signal is a signal FLR answering signal FLR RSP (i.e., indicator = 10), there may be added additional indicators such as the index direction of a received signal FLR RSP. When the indicator indicates that the received signal is a signal FLR RSP (indicator = 01), then can be added additional indicators (for example, indexes direction of received signals FLR, indexes direction signals FLR RSP).

Table 2 below shows an example of indicator signals.

If there is only one direction of transmission for the VLC device, bits 2-4 and 5-7 default is set to '000'.

Fig. 23 depicts an example of passing a two-way flow of messages FLR according to the variant example of implementation of the disclosure. The device is A VLC (MN or AP) communicates with device B VLC (MN or AP). Initially, device A and device B are connected and communicate bi-directional manner in the X direction (step 1710). At some point, you start condition, which leads to the initiation of fast reconnection. For example, the device A transmits a message 1720 data and message 1730 with the data and does not receive the ACK message for any of these data messages.

In response to a trigger condition, the device A transmits one or more signals FLR on device B according to the multitude of directions used by the device a and device B, including illustrative signal 1640 FLR. Each signal FLR contains the index direction. When ustroystvo detects signals FLR, coming, for example, from multiple directions, the device B selects one or more signals FLR, who will be responsible (step 1745), and responds by transmitting a variety of signals, response (RSP) FLR, including illustrative response signal 1750 FLR on device A. Each signal FLR RSP contains the indices of the directions of the signals received FLR and the index of the direction of the signal FLR RSP. After that, the device selects A new direction(I) transmission (TX) (step 1755). Device A may choose the direction of the TX signal FLR adopted by device B, or the direction of the TX signal FLR RSP taken from device B. Device A can choose one of many signals FLR RSP, which will be responsible (step 1760).

Device A then transmits the many new FLR signals to the device B, including illustrative signal 1765 FLR. Each new signal 1765 FLR contains the index of the direction of the new FLR signal and the index(s) direction signals FLR RSP previously received from the device B. the Device B can choose the direction of the TX signal FLR RSP adopted by A device, or the direction of the TX device B (step 1770). Device A and device B resume bidirectional communication on a new chosen direction(s) (step 1780).

In another embodiment, the disclosure, if the VLC device that runs fast reconnection, is close to other devices VL, running the VLC device may send signals to other devices (e.g., via the backhaul) and ask other VLC device to send signals to FLR. The target device is VLC, which sends a signal FLR RSP sends a signal FLR RSP many neighboring devices from which the target device receives the signal FLR. Then, the VLC device, receiving the signal FLR RSP, notify the triggering device. The triggering device can then establish an additional connection to the selected new neighboring device that has the best connection.

In another embodiment, the disclosure, if some MN is not scheduled any resources, because the dims AP reduces the transmission rate, the AP instructs such MN to suspend the service or switch to other devices or AP, or AP informs the MN about other available resources, such as other color bandwidth or other areas. Other directions (or angles) can be, for example, from the other light emitting diodes (LED) AP.

In another embodiment, the disclosure model decrease the brightness of the lighting fixtures should be specified devices with which light devices communicate in the VLC system. Then, on the side of the MN, the MN can reconfigure timers reconnection model, smart is the relationship of brightness.

In another embodiment, the disclosure timers and limit counter NACK/ACK can be configured based on various factors (e.g., models decrease the brightness, type a traffic/service), using a predefined algorithm, known AP and MN. Alternatively, the AP can configure the timers and counters and then explicitly pass configuration of the MN.

In all variants of the implementation of the above device (MN or AP) instead stop sending data when the triggering conditions FLR can continue to send data and, at the same time, initiates a process of rapid reconnection to help restore the connection.

In another embodiment, the disclosure algorithm color selection or choice of direction/angle may use a measure of the quality of the channel as the input parameters. The signal FLR RSP can be used to measure the quality of the channel.

In another embodiment, the disclosure of the above-mentioned embodiments of using some or all of the available colors or directions can be combined with the battery life, as discussed above, to decide what device sends signals FLR or FLR RSP.

In another embodiment, the disclosure, if the light emitting diode (LED) or multiple light emitting diodes (LED) have the option of an adjustable field of view (FOV), more bol is large FOV is preferable to use to restore the connection for sending signals FLR or FLR RSP. Can be used more robust coding scheme or modulation to send signals FLR or FLR RSP. The device can be rotated or shifted to obtain the connection is restored.

Although the present disclosure has been described using the example of a variant implementation, experts in the field of technology can be a variety of changes and modifications. It is assumed that the present disclosure encompasses such changes and modifications that fall within the scope of the appended claims.

1. The way to restore the connection in the first communication device based on the visible light (VLC) for use in the VLC system, comprising stages:
detection of the start condition indicating a failure of the connection VLC associated with the first selected resources used for communication with the second VLC device;
completion of the first allocated resources for data transmission to the second VLC device;
signal transfer fast reconnection (FLR), using the first allocated resources;
signal response fast reconnection (FLR RSP), indicating that the second VLC device took FLR signal; and
resume in the first VLC device data to the second VLC device in response to receiving the signal FLR RSP.

2. The method according to claim 1, wherein the trigger condition is one which m of the following:
failure of reception of the first VLC device of the first number of the ACK signals transmitted by the second VLC device;
receiving the first VLC device of the second number of consecutive NACK signals transmitted by the second VLC device;
failure of reception of the first VLC device at least one of the ACK signal and the NACK signal transmitted by the second VLC device within a predetermined interval of time;
receiving consistent messages containing errors from the second VLC device; and
determining that the quality of the connection channel VLC below the threshold value.

3. The method according to claim 1, further comprising the steps:
transmitting the first VLC device to the second VLC device status of the first battery associated with the battery of the first VLC device; and
receiving in the first VLC device from the second VLC device status of the second battery associated with the battery of the second VLC device,
the first VLC device transmits a signal FLR, using the first allocated resources only if the status of the first battery and the second status of the battery indicates that the battery life of the first VLC device is greater than the battery life of the second VLC device,
if the status of the first battery and the second status of the battery indicates that the battery life of the first VLC device is not greater than the battery life of the second VLC device:
the first VLC device is not in front of the em signal FLR second VLC device; and
the first VLC device receives the incoming signal FLR from the second VLC device.

4. The method according to claim 1, in which the phase of the signal transmission FLR contains the transmission of the first VLC device multiple signals FLR on the set of available color bandwidths.

5. The method according to claim 4, in which the phase of the reception signal FLR RSP contains the reception of the first VLC device signal FLR RSP transferred to the second VLC device, at least one of the many available color bandwidths.

6. The method according to claim 5, in which the step of resuming the data transmission, the first VLC device to the second VLC device contains resumes transmission on the selected at least one from a set of available color bandwidths.

7. The method according to claim 1, in which the phase of the signal transmission FLR contains the transmission of the first VLC device multiple signals FLR in myriad ways.

8. The method according to claim 7, in which the phase of the reception signal FLR RSP contains the reception of the first VLC device signal FLR RSP transferred to the second VLC device in at least one of the multiple directions.

9. The method according to claim 7, in which the step of resuming the data transmission, the first VLC device to the second VLC device contains resumes transmission in the selected at least one from many directions.

10. The method according to claim 1, in which the start condition is a failure of reception of the ACK sarane the specified number of times in a row.

11. The method according to claim 1, in which the FLR signal includes a direction index of multiple light emitting diodes (LED), which have different angles.

12. The communication device based on the visible light (VLC) for use in the VLC system, containing:
a control unit receiving the transmission to control the transmission and reception of data; and
the control unit connection to detect a trigger condition indicating a failure of the connection VLC associated with the first selected resources used for communication with another device, VLC, stopping at the first selected resource data referred to another VLC device in response to the detection, signal transfer fast reconnection (FLR), using the first allocated resources, receive feedback fast reconnection (FLR RSP), indicating that referred to another device VLC took FLR signal, and resume transmission of the data referred to another VLC device in response to receiving the signal FLR RSP.

13. The VLC device according to item 12, in which the trigger condition is one of the following:
the failure of the device VLC first number of the ACK signals transmitted referred to another device VLC;
the device VLC second number of consecutive NACK signals transmitted referred to another device VLC;
failure of reception by the VLC device at least one of the of igala ACK / NACK signal, transferred mentioned another VLC device within a predetermined interval of time;
receiving consistent messages containing errors from the other VLC device; and
determining that the quality of the connection channel VLC below the threshold value.

14. The VLC device according to item 12, in which the control unit connection transmits referred to another device VLC the status of the first battery associated with the battery VLC device, and receives from the other device VLC status of the second battery associated with the battery referred to another device VLC;
when the control unit connection transmits a signal FLR, using the first allocated resources only if the status of the first battery and the second status of the battery indicates that the battery life of the device VLC is greater than the battery life mentioned another device VLC;
if the status of the first battery and the second status of the battery indicates that the battery life of the device VLC is not greater than the battery life mentioned another VLC device, the control unit connection does not pass the signal FLR referred to another device, VLC, and VLC device receives the incoming signal from FLR referred to another device VLC.

15. The VLC device according to item 12, in which the control unit connection transmits multiple signals FLR on the set of available colors is x bandwidth receives the signal FLR RSP on at least one of the many available color bandwidths, and resumes the transmission of the selected at least one from a set of available color bandwidths.

16. The VLC device according to item 15, in which the control unit connection transmits multiple signals FLR in myriad ways.

17. The VLC device according to clause 16, in which the control unit connection signal is received from the FLR RSP transmitted referred to another device in VLC at least one of the multiple directions, and resumes the transmission of the selected at least one from many directions.

18. The VLC device according to item 12, in which the start condition is a failure of reception of the ACK for some predetermined number of times in a row.

19. The VLC device according to item 12, in which the FLR signal includes a direction index of multiple light emitting diodes (LED), which have different angles.