Data unit processing method and communication device that uses the data unit processing method

Abstract

comprising a data unit processing method performed by a first communication device: Configuring a data unit by the first communication device, wherein the data unit has: a preamble to a specific format that adheres to an initial package format; and a symbol portion that includes at least one symbol and adheres to a Wi-Fi Long Range packet format; wherein the preamble of the specific format can be decoded according to a first communication standard and the symbol part can be processed according to a Wi-Fi long-range mode; wherein a length of the symbol part can be determined according to the preamble of the specific format and the symbol part can be identified according to identification information in the symbol part; the data unit processing method further exhibits: Adjusting a power level of the preamble of the specific format by the first communication device to meet a request from a receiver of a second communication device before the data unit is sent to the second communication device; where the first packet format is a Wi-Fi legacy packet format, and the first communication standard is a Wi-Fi legacy mode; and the data unit processing method further exhibits: Adjusting the length of a length field in a legacy signal field (L-SIG) of the preamble of the specific format by the first communication device to adjust the power level.

Description

Cross-reference to related registrations

[0001] This application claims priority over preliminary US application No. 62 / 595,125, filed on June 12, 2017, the contents of which are incorporated herein by reference. background

[0002] A long-range Wi-Fi system has better sensitivity than a legacy Wi-Fi system and can therefore transmit packets over a greater distance. However, the packets of the long-range Wi-Fi system follow a packet format that differs from that of the legacy Wi-Fi system. Therefore, the legacy Wi-Fi system could not identify the long-range Wi-Fi packet and could not successfully decode it when long-range Wi-Fi packets arrived.

[0003] Accordingly, the hardware of a conventional legacy Wi-Fi system is independent of the hardware of a conventional long-range Wi-Fi system, which increases the cost of a wireless communication system and causes inconvenience for users.

[0004] Therefore, a new radio communication method is needed.

[0005] Document WO 2017 / 160774 A1 discloses a data unit comprising a first part and a second part. The first part contains a legacy preamble. The second part comprises an LRLP (Long-Range-Low-Power) preamble and LRLP data. A similar data unit is also known from each of documents US 2015 / 0023449 A1 and US 2015 / 0350950 A1. Summary

[0006] Therefore, one objective of the present application is to provide a data unit processing method and a communication system that can construct a data unit that can be received according to a Wi-Fi legacy mode and decoded according to a Wi-Fi long-range mode.

[0007] Therefore, one objective of the present application is to provide a data unit processing method and a communication system that can receive a legacy preamble and a signal according to a Wi-Fi legacy mode and can decode the long-range data unit according to a Wi-Fi long-range mode.

[0008] Two data processing methods and two corresponding communication devices according to the present invention are defined in the independent claims. The dependent claims define further developments of the present invention.

[0009] An embodiment of the present application discloses a data unit processing method performed by a first communication device, comprising: configuring a data unit by the first communication device, wherein the data unit comprises: a preamble of a specific format that conforms to a first packet format; and a symbol part comprising at least one symbol and conforming to a Wi-Fi long-range packet format. The preamble of the specific format can be decoded according to a first communication standard, and the symbol can be processed according to a Wi-Fi long-range mode. The length of the symbol part can be determined according to the preamble of the specific format, and the symbol part can be identified according to identification information contained in the symbol part.

[0010] Another embodiment of the present application discloses a communication device comprising: a control circuit configured to execute program codes stored in a storage device to configure a data unit comprising: a preamble of a specific format that conforms to a first packet format; and a symbol part comprising at least one symbol and conforming to a Wi-Fi long-range format. The preamble of the specific format can be decoded according to a first communication standard, and the symbol can be processed according to a Wi-Fi long-range mode. The length of the symbol part can be determined according to the preamble of the specific format, and the symbol part can be identified according to identification information contained within the symbol part.

[0011] Another embodiment of the present application discloses a data unit decoding method, performed by a communication device, for decoding a data unit comprising a preamble of a specific format that conforms to a first packet format and a symbol part with at least one symbol that conforms to a Wi-Fi Long Range packet format, comprising: (a) processing the preamble of the specific format to determine a length of the symbol part and determining, according to identification information contained in the symbol part, whether the symbol part conforms to the first packet format or the Wi-Fi Long Range packet format; (b) applying a first communication standard to decode the symbol part if the symbol part conforms to the first packet format; and (c) applying a Wi-Fi Long Range mode to process the symbol part if the symbol part conforms to the Wi-Fi Long Range packet format.

[0012] Yet another embodiment of the present application discloses a communication device for decoding a data unit, comprising a preamble of a specific format that conforms to a first packet format and a symbol part with at least one symbol that conforms to a Wi-Fi long-range packet format, comprising: a control circuit configured to execute program codes stored in a storage device to perform: (a) processing the preamble of the specific format to determine a length of the symbol part and determining, according to identification information contained in the symbol part, whether the symbol part conforms to the first packet format or the Wi-Fi long-range packet format; (b) applying a first communication standard to decode the symbol part if the symbol part conforms to the first packet format;and (c) applying a Wi-Fi Long Range mode to process the symbol part if the symbol part conforms to the Wi-Fi Long Range packet format.;

[0013] In light of the aforementioned embodiments, the Wi-Fi long-range packet and the Wi-Fi legacy packet can be received and processed by a single communication device, thus solving the conventional problem. However, the present invention is not limited to solving such problems.

[0014] These and other problems of the present invention will undoubtedly become apparent to those with ordinary knowledge in the field after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings. Brief description of the drawings Fig.Figure 1 is a schematic diagram representing a mixed package according to an embodiment of the present application. Fig. Figure 2A is a schematic diagram representing a mixed package according to another embodiment of the present application. Fig. 2B is a schematic diagram representing a conventional Wi-Fi legacy packet format. Fig. Figure 3 is a schematic diagram showing the lengths of basic data units of an L-STF and an LR-STF. Fig. 4 and Fig. Figure 5 are block diagrams representing a communication system according to different embodiments of the present application, comprising a first communication device that sends a mixed packet and a second communication device that receives the mixed packet. Fig.Figure 6 is a block diagram that represents an exemplary structure of the communication devices used in Fig. 4 and Fig. 5 is shown. Detailed description

[0015] In the following embodiments, each component can be implemented by hardware (e.g., a circuit or a device) or hardware with software (e.g., a processor equipped with at least one program). Furthermore, each component can be subdivided into more components or integrated into fewer components. Additionally, the terms "first" and "second" are used in each embodiment only to identify different components and do not imply any order between them.

[0016] Fig.Figure 1 is a schematic diagram representing a mixed package according to an embodiment of the present application. It should be noted that some common parts of the package, such as the preamble and data usage information, have been omitted for simplification. However, those with knowledge in the field will recognize that other common parts can be added to the package shown in the embodiment. As in Fig. As shown in Figure 1, the mixed packet PLR has a preamble Pr of a specific format that adheres to a first packet format, and a symbol part SYP that has at least one symbol SY and adheres to a Wi-Fi Long Range packet format. In other words, the symbol part SYP in Fig. 1. A Wi-Fi long-range package.

[0017] The preamble Pr of the specific format can be decoded according to a first communication standard, and the symbol part SYP can be processed according to a Wi-Fi Long Range mode (e.g., IEEE 802.11ax standard), or a proprietary mode can process a Wi-Fi Long Range packet. The length (or a named amount of data) of the symbol part SYP can be determined according to the preamble Pr of the specific format.

[0018] Furthermore, the SYP symbol fragment can be identified according to the identification information contained within it. Specifically, this identification information can determine whether the SYP symbol fragment adheres to the Wi-Fi Long Range packet format or the first packet format.

[0019] Fig. 2A is a schematic diagram showing a mixed package

[0020] PLR according to another embodiment of the present application. In this embodiment, the preamble Pr of the specific format is a legacy-compatible preamble that adheres to a Wi-Fi legacy packet format. However, the preamble Pr of the specific format can adhere to a packet format that corresponds to different requirements. As in Fig. As shown in Figure 2A, the preamble Pr of the specific format is a legacy-compatible preamble that includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), and an L-SIG (Legacy Signal Field).

[0021] The L-STF can be used for packet detection and automatic gain control. The L-LTF can also be used for channel calculation. Additionally, the L-SIG can be used to identify the SYP symbol part. Details are provided in... Fig.Figure 2A shows that the L-SIG has a rate field, a length field, and a remainder. As mentioned above, the length of the symbol part SYP can be determined according to the preamble Pr of the specific format. In one embodiment, the length of the symbol part SYP can be determined according to the rate field and the length field in the L-SIG.

[0022] It was back on Fig. 2A is referenced. As mentioned above, the symbol part SYP adheres to a Wi-Fi long-range packet format, which includes an LR-STF (Long-Range Short Training Field), an LR-LTF (Long-Range Long Training Field), an LR-SIG (Long-Range Signal Field), and an LR payload (data). The LR-STF, the LR-LTF, the LR-SIG, and the LR payload each contain at least one symbol SY, which is described in Fig. 1 is shown.

[0023] The LR-STF can be used for packet detection and automatic gain control. The LR-LTF can also be used for channel calculation. Additionally, the LR-SIG can be used to identify the symbol part SYP. In one embodiment, the LR-SIG can have the same data structure as the L-SIG. As mentioned above, the symbol part SYP can be identified according to identification information contained within the symbol part SYP. In one embodiment, the identification information is a specific pattern contained within the LR-STF.

[0024] In one embodiment, in the same communication system, alongside the mixed packet PLR, there exists the following: Fig. 2A shows a packet that adheres to the Wi-Fi legacy packet format. Fig. Figure 2B is a schematic diagram representing a conventional Wi-Fi legacy packet format. As shown in Fig.As shown in 2B, the legacy package LL has a Pr of a specific format and a symbol part SYP. This is similar to the mixed package PLR ​​in Fig. 2A also has the L-STF, L-LTF, and L-SIG in the Pr of the specific format. However, the SYP symbol part of the legacy packet LL has the L-STF, L-LTF, L-SIG, and PLR mixed packet data instead of the L-STF, L-LTF, L-SIG, and PLR data. Fig. 2A has an L-payload (data). In one embodiment, the symbol part SYP has in Fig. 2B does not exhibit the aforementioned specific pattern, thus determining it to be data instead of a Wi-Fi Long Range packet.

[0025] Therefore, when a communication device in such a communication system receives a packet, the communication device first uses Wi-Fi legacy mode (e.g., IEEE 802.11) to process the preamble Pr of the specific format to determine the length of the symbol part SYP. Then, based on the identification information contained in the symbol part SYP, the communication device determines which packet format the symbol part SYP adheres to. If the packet is the legacy packet LL, which is in Fig. As shown in Figure 2B, the communication device can determine that the symbol part SYP conforms to the Wi-Fi legacy packet format and proceeds to use Wi-Fi legacy mode to process the data following the preamble of the specific format.

[0026] If, on the other hand, the communication device determines that the SYP symbol portion conforms to the Wi-Fi Long Range packet format, it switches to Wi-Fi Long Range mode to process the subsequent SYP symbol portion. The "process" here can mean decoding the SYP symbol portion that conforms to the Wi-Fi Long Range packet format or forwarding the packet to another communication device. Related operations are described below.

[0027] In one embodiment, the length of a basic data unit of an LR-STF of the symbol part SYP differs from that of a basic data unit of an L-STF of the preamble Pr of the specific format. In other words, the data periods of the L-STF and the LR-STF are different. Fig. Figure 3 is a schematic diagram representing the lengths of the basic data units of an L-STF and an LR-STF. We in Fig.As shown in Figure 3, the L-STF and the LR-STF have the same lengths, but the L-STF consists of four basic data units S1-S4, while the L-STF consists of three basic data units S1-S3. In other words, the data period of the L-STF is 1 / 4, and the data period of the LR-STF is 1 / 3. Thus, the L-STF and the LR-STF can be distinguished based on the lengths of their basic data units.

[0028] Fig. 4 and Fig. Figure 5 are block diagrams representing a communication system according to an embodiment of the present application, comprising a first communication device C_1 that sends a mixed packet PLR and a second communication device C_2 that receives the mixed packet PLR. As shown in Fig.As shown in Figure 4, the communication system 400 comprises a first communication device C_1 and a communication device C_2. The first communication device C_1 sends a mixed packet PLR to the second communication device C_2. The first communication device C_1 can also send a legacy packet LL to the second communication device C_2.

[0029] Therefore, after receiving the packet, the second communication device C_2 first uses Wi-Fi legacy mode to process the preamble Pr of the specific format in order to determine the length of the symbol part SYP. Then, based on the identification information contained in the symbol part SYP, communication device C_2 determines which packet format the symbol part SYP adheres to. If the packet is the legacy packet LL, communication device C_2 can determine that the symbol part SYP adheres to the Wi-Fi legacy packet format and proceeds to use Wi-Fi legacy mode to decode the data following the preamble of the specific format.

[0030] In contrast, when communication device C_2 receives the mixed packet PLR, it switches to Wi-Fi Long Range mode to process the following symbol part SYP. As mentioned above, the "process" here can mean decoding the symbol part SYP based on Wi-Fi Long Range mode or forwarding the symbol part SYP to another communication device. In one embodiment, communication device C_2 is a legacy communication device. Communication device C_2 receives the mixed packet PLR and determines the length of the symbol part SYP according to the preamble Pr of the specific format. Communication device C_2 then continues to receive the symbol part SYP based on the determined length but could not decode the symbol part SYP because it can only use Wi-Fi Legacy mode.The symbolic part SYP, which is a Wi-Fi Long Range packet, is forwarded to another communication device, while communication device C_2 receives the symbolic part SYP. In such a case, instead of the symbolic part SYP, the mixed packet PLR can be forwarded to the other communication device, while communication device C_2 receives the symbolic part SYP.

[0031] In such an embodiment, the first communication device C_1 can be a communication device that can construct the mixed packet PLR or the legacy packet LL such that an STA (station) can maintain Wi-Fi legacy mode or Wi-Fi long-range mode. Furthermore, the first communication device C_1 can be a communication device that can receive the mixed packet PLR or the legacy packet LL and forward the mixed packet PLR or the legacy packet LL to the second communication device C_2, just as a master STA can control a Wi-Fi long-range STA and a Wi-Fi legacy STA.

[0032] As in Fig.As shown in Figure 5, communication system 500 comprises a first communication device C_1, a second communication device C_2, and a third communication device C_3. The first communication device C_1 sends a mixed packet PLR to the second communication device C_2. Additionally, the third communication device C_3 sends a legacy packet LL to the second communication device C_2.

[0033] Therefore, after receiving the packet, the second communication device C_2 first uses Wi-Fi legacy mode to process the preamble Pr of the specific format in order to determine the length of the symbol part SYP. Then, based on the identification information contained in the symbol part SYP, communication device C_2 determines which packet format the symbol part SYP adheres to. If the packet is the legacy packet LL, communication device C_2 can determine that the symbol part SYP adheres to the Wi-Fi legacy packet format and proceeds to use Wi-Fi legacy mode to process the data following the preamble Pr of the specific format.

[0034] In contrast, when communication device C_2 receives the mixed packet PLR, it switches to Wi-Fi Long Range mode to process the subsequent symbol part SYP. As mentioned above, the "process" here can mean decoding the symbol part SYP based on Wi-Fi Long Range mode or forwarding the symbol part SYP (or the mixed packet PLR) to another communication device. In one embodiment, communication device C_2 is a legacy communication device. Communication device C_2 receives the mixed packet PLR and determines the length of the symbol part SYP according to the preamble Pr of the specific format. Communication device C_2 then continues to receive the symbol part SYP based on the determined length but could not decode the symbol part SYP because it can only use Wi-Fi Legacy mode.The symbol part SYP, which is a Wi-Fi long-range packet, is forwarded to another communication device, while the communication device C_2 receives the symbol part SYP.

[0035] In such an embodiment, the first communication device C_1 can be a communication device that can construct the mixed packet PLR such that an STA (station) can use the Wi-Fi long-range mode. In addition, the first communication device C_1 can be a communication device that can receive the mixed packet PLR and forward the mixed packet PLR to the second communication device C_2, just as a master STA can control a Wi-Fi long-range STA and a Wi-Fi legacy STA.

[0036] Furthermore, in such an embodiment, the third communication device C_3 can be a communication device that can construct the legacy packet LL such that an STA can use Wi-Fi legacy mode. Additionally, the third communication device C_3 can be a communication device that can receive the legacy packet LL and forward the legacy packet LL to the second communication device C_2, just as a master STA can control a Wi-Fi long-range STA and a Wi-Fi legacy STA. It should be noted that the scope of the present invention is not limited to the communication devices C_1 and C_2 described in Fig. 4 and Fig. 5 are shown.

[0037] Fig. 6 is a block diagram that represents an exemplary structure of the communication device that is in Fig. 4 and Fig. 5 is shown. As in Fig.As shown in Figure 6, the communication device 600 comprises a storage device 601, a control circuit 603, and a transmission interface 605. The storage device 601 stores at least one program code, and the control circuit 603 reads the program code to execute the aforementioned embodiments. Furthermore, the transmission interface 605 is configured to send and receive signals. The communication device 600 can be implemented as the first communication device C_1 and the second communication device C_2, which are described in Figure 6. Fig. 4 and Fig. Figure 5 shows the first communication device C_1 and the second communication device C_2, which are shown in Fig. 4 and Fig. 5 are shown, but are not related to those in Fig. 6 illustrated structure limited.

[0038] In one embodiment, at least a portion of the mixed packet PLR can be adapted to provide improved transmit or receive quality. For example, the power level of the preamble Pr of the specific format can be adjusted by the first communication device C_1 to meet a requirement of a receiver of the second communication device C_2 before the mixed packet PLR is sent to the second communication device C_2. For example, the power level is adjusted to meet the peak-to-average power ratio (PAPR) of the receiver. In one embodiment, the length of a length field in the L-SIG can be modified to adjust the power level. In another embodiment, the power level of the symbol portion SYP can also be adjusted.

[0039] In another embodiment, the duration (i.e., the length) of the LR-STF and the LR-LTF can be modified to extend the transmission distance of the mixed packet PLR. For example, if a longer transmission distance is desired, the duration of the LR-STF and the LR-LTF can be lengthened so that the mixed packet PLR can be easily captured. Conversely, if only a shorter transmission distance is needed, the duration of the LR-STF and the LR-LTF can be shortened. Such an operation can be called dynamic long-short switching.

[0040] In yet another embodiment, at least one symbol of the symbol part SYP is frequency-multiplied or time-multiplied to improve the transmission capability of the mixed packet PLR. For example, the LR-STF, the LR-LTF, the LR-SIG, and the LR-Payload can be time-multiplied, and the LR-SIG and the LR-Payload can be frequency-multiplied.

[0041] In yet another embodiment, an encoding rate of at least one symbol of the symbolic part SYP is used to improve the robustness of the symbolic part SYP. The encoding rate represents the ratio of redundant data to actual data. The higher the ratio of redundant data to actual data, the greater the robustness. Conversely, the lower the ratio of redundant data to actual data, the lower the robustness. Since a mixed packet format PLR can ensure successful transmission, only a lower encoding rate, such as BCC 1 / 4 or LDPC 1 / 4, is required.

[0042] Table 1 below illustrates an example showing the relationship between the adaptation steps and the part on which the adaptation steps are performed. The symbol "Y" indicates that the adaptation can be performed on the corresponding part. For example, the power level of the Rr of the specific format can be adapted, and the LR-STF can be time-multiplied. It should be noted that the following table is only an example and does not imply any limitation to the scope of the present application. For example, the preamble of the specific type can be time-multiplied if necessary. Table 1 Pr LR-STF LR-LTF LR-SIG LR Payload Power level Y Y Y Y Y Coding rate Y Y Time multiplication Y Y Y Y Frequency multiplication Y Y Dynamic long-short switching Y Y

[0043] The communication system may contain packets that, in addition to the aforementioned packet formats, adhere to other packet formats, such as the HT mixed format or the HT greenfield format. However, the aforementioned mixed packet PLR can still be identified by the preamble of the specific format of packets that adhere to other packet formats.

[0044] Packets are used as examples of the aforementioned embodiments, but other types of data units may replace the aforementioned packets.

[0045] In light of the aforementioned embodiments, the Wi-Fi long-range packet and the Wi-Fi legacy packet can be received and processed by a single communication device, thus solving the conventional problem. However, the present invention is not limited to solving such problems.

[0046] Those with expertise in the field will readily recognize that numerous modifications and alterations to the apparatus and method can be made while retaining the teachings of the invention. Accordingly, the foregoing disclosure should be considered as limited only by the dimensions and limits of the appended claims.

Claims

[1] comprising a data unit processing procedure performed by a first communication device: Configuring a data unit by the first communication device, wherein the data unit has: a preamble to a specific format that adheres to an initial package format; and a symbol portion that includes at least one symbol and adheres to a Wi-Fi Long Range packet format; wherein the preamble of the specific format can be decoded according to a first communication standard and the symbol part can be processed according to a Wi-Fi long-range mode; wherein a length of the symbol part can be determined according to the preamble of the specific format and the symbol part can be identified according to identification information in the symbol part; the data unit processing method further exhibits: Adjusting a power level of the preamble of the specific format by the first communication device to meet a request from a receiver of a second communication device before the data unit is sent to the second communication device; where the first packet format is a Wi-Fi legacy packet format, and the first communication standard is a Wi-Fi legacy mode; and the data unit processing method further exhibits: Adjusting the length of a length field in a legacy signal field (L-SIG) of the preamble of the specific format by the first communication device to adjust the power level. [2] Data unit processing method according to claim 1, further comprising: Adjusting the duration of a Long Range Short Training Field (LR-STF) and a Long Range Long Training Field (LR-LTF) of the symbol portion by the first communication device. [3] Data unit processing method according to claim 1, further comprising: Frequency multiplication or time multiplication of at least one symbol of the symbol part by the first communication device. [4] Data unit processing method according to claim 1, further comprising: Adjustment of an encoding rate of at least one symbol of the symbol part by the first communication device. [5] Data unit processing method according to claim 1, wherein the length of a basic data unit of an LR-STF of the symbol part differs from a basic data unit of an L-STF of the preamble of the specific format. [6] Data unit processing method according to claim 1, wherein the identification information is contained in an LR-SIG (Long-Range Signal Field) of the symbol part. [7] Data unit processing method performed by a communication device for processing a data unit comprising a preamble of a specific format that conforms to a first packet format and a symbol part comprising at least one symbol that conforms to a Wi-Fi Long Range packet format, comprising: (a) Processing the preamble of the specific format to determine a length of the symbol part and determining, according to identification information contained in the symbol part, whether the symbol part conforms to the first packet format or the Wi-Fi Long Range packet format; (b) Applying a first communication standard to decode the symbolic part if the symbolic part conforms to the first packet format; and (c) Applying a Wi-Fi Long Range mode to process the symbol part if the symbol part conforms to the Wi-Fi Long Range packet format; wherein a power level of the preamble of the specific format is adjusted by a first communication device to meet a request from a receiver of the communication device, which is a second communication device, before the data unit is sent to the second communication device; where the first packet format is a Wi-Fi legacy packet format, and the first communication standard is a Wi-Fi legacy mode; and wherein the length of a length field in a legacy signal field (L-SIG) of the preamble of the specific format is adjusted by the first communication device to adjust the power level. [8] Data unit processing method according to claim 7, wherein the identification information is contained in an LR-SIG (Long-Range Signal Field) of the symbol part. [9] Data unit processing method according to claim 7, further comprising: Using a communication device to forward the symbol part to another communication device while the communication device receives the symbol part. [10] Communication device comprising: a control circuit that is set up to execute program codes stored in a storage device to configure a data unit that has: a preamble to a specific format that adheres to an initial package format; and a symbol portion that includes at least one symbol and adheres to a Wi-Fi Long Range packet format; wherein the preamble of the specific format can be processed according to a first communication standard and the symbol can be processed according to a Wi-Fi long-range mode; wherein a length of the symbol part can be determined according to the preamble of the specific format and the symbol part can be identified according to identification information in the symbol part; wherein the control circuit is further configured to adjust a power level of the preamble of the specific format by the communication device, which is a first communication device, in order to meet a request from a receiver of a second communication device to be able to receive the data unit; where the first packet format is a Wi-Fi legacy format and the first communication standard is a Wi-Fi legacy mode; and wherein the control circuit is further configured to adjust a length of a length field in a legacy signal field (L-SIG) of the preamble of the specific format by the first communication device in order to determine the power level. [11] Communication device according to claim 10, wherein the control circuit is further configured to adjust the duration of a long-range short training field (LR-STF) and a long-range long training field (LR-LTF) of the symbol part by the first communication device in order to extend a transmission distance of the data unit. [12] Communication device according to claim 10, wherein the control circuit is further configured to frequency-multiply or time-multiply at least one symbol of the symbol part by the first communication device in order to improve the transmission capability of the data unit. [13] Communication device according to claim 10, wherein the control circuit is further configured to adjust the encoding rate of at least one symbol of the symbol part by the first communication device in order to improve the robustness of the symbol part. [14] Communication device according to claim 10, wherein the length of a basic data unit of an LR-STF of the symbol part differs from a basic data unit of an L-STF of the preamble of the specific format. [15] Communication device according to claim 10, wherein the identification information is contained in an LR-SIG (Long-Range Signal Field) of the symbol part. [16] Communication device for processing a data unit comprising a preamble of a specific format that complies with a first packet format and at least one symbol that complies with a Wi-Fi long-range packet format, comprising: a control circuit that is set up to execute program codes stored in a memory device to perform: (a) Processing the preamble of the specific format to determine a length of the symbol part and determining, according to identification information contained in the symbol part, whether the symbol part conforms to the first packet format or the Wi-Fi Long Range packet format; (b) Applying a first communication standard to decode the symbolic part if the symbolic part conforms to the first packet format; and (c) Applying a Wi-Fi Long Range mode to process the symbol part if the symbol part conforms to the Wi-Fi Long Range packet format; wherein a power level of the preamble of the specific format is adjusted by a first communication device to meet a request from a receiver of the communication device, which is a second communication device, before the data unit is sent to the second communication device; where the first packet format is a Wi-Fi legacy packet format, and the first communication standard is a Wi-Fi legacy mode; and wherein the length of a length field in a legacy signal field (L-SIG) of the preamble of the specific format is adjusted by the first communication device to adjust the power level. [17] Communication device according to claim 16, wherein the identification information is contained in an LR-SIG (Long-Range Signal Field) of the symbol part. [18] Communication device according to claim 16, wherein the control circuit is further configured to: Controlling the communication device to forward the symbol part to another communication device while the communication device receives the symbol part.

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