TWI337813B - Role exchange method for bluetooth system - Google Patents

Description

IX. Description of the Invention: [Technical Field] The present invention relates to a role exchange method, and particularly relates to a role exchange method for Bluetooth wireless communication, which can effectively avoid interference of noise. [Prior Art] Bluetooth is a technology applied to wireless personal area networks. It is designed to eliminate the need to install cables and connectors between various devices. It can be applied to personal computers and their peripherals, to the Walkman and its connected headphones. Bluetooth provides rugged, secure, and data- and sound-enabled radio communications that don't need to be in line with each other. Please refer to Figure 1 for a schematic diagram of the packet transfer process for the successful exchange of roles in the conventional Bluetooth specification. On the time axis ti, the slave unit (Slave) requests to exchange roles and sends a synchronized frequency hopping packet, and the main unit (Master) sends back an acknowledgment packet. On the time axis t2, after the main unit/subsidiary unit is converted into a new auxiliary unit/new primary unit, a polling packet is sent by the new primary unit, and the new auxiliary unit receives a polling packet from the new primary unit. Send an empty packet and complete the action of the entire exchange role. Bluetooth uses the 2,4 GHz ISM band and shares the same frequency band as the IEEE 802.11 family of wireless LANs. Mutual interference between the two networks may occur unexpectedly, which will severely degrade each other's performance. Refer to Figure 2, which shows the possible interference caused by noise interference when the packet is exchanged.

6 The impact of ISS-P060010-TW, that is, the schematic diagram of the packet transmission process in which the exchange role fails in the conventional Bluetooth specification. When the time axis is tl, the attached unit requests to exchange roles and send a synchronized hopping packet, and the main unit sends back an acknowledgment packet, but the acknowledgment packet reception failure is caused by noise or external influence. However, after transmitting the acknowledgment packet, the main unit automatically converts to the new affiliation unit at the time axis t2, but the original affiliation unit still does not receive the acknowledgment packet, and it is considered that the synchronized hopping packet is not delivered, so in the time axis t2 The synchronized frequency hopping packet is then resent. However, since the original primary unit has been switched to the new attached unit, the adjacent unit and the new attached unit will no longer receive each other's packets. Until the time axis t3, at this time, the exchange role time (newconnectionTO) has been exceeded, and the new subsidiary unit and the affiliate unit each return to the original primary unit and the attached unit, and the action of the exchanged role is declared to fail. There are no clear-cut prevention mechanisms in the Bluetooth standard for the problems that may be faced in this regard. Therefore, in order to solve this problem, it is necessary to provide a new role exchange method to overcome the shortcomings of the prior art. As a result of the job, the applicants carefully studied and researched, and in a spirit of perseverance, finally developed a method of exchange of strong roles to avoid the failure of role exchange due to noise interference. SUMMARY OF THE INVENTION The main object of the present invention is to provide a role exchange method for solving the problem of failure of a role exchange program due to external interference when exchanging characters in the traditional Bluetooth specification.

7 ISS-P060010-TW w/813 line through the purpose of the present invention provides 1 for "benefit package 仏 ^ i is an early % request exchange role and send a 1-step jump collar seal ^ to a first main unit; The second time t = the frequency hopping should be switched to - the second subsidiary list & the first subsidiary unit

The frequency seal j is repeatedly transmitted a plurality of times; and the first-affiliated unit is automatically switched to a second main unit. The day r is according to a feature of the present invention, wherein the following step: after the third time t3, a main : Contains a private spoon ♦ 结交田 This brother is a major early yuan delivery round 2 packets 'The second subsidiary unit receives the packet from the second = * rot groove after sending - empty to the second main unit. == Another feature of Ming, which is the third time. In the second time t3, the second time t3 needs to be less than the exchange role time. According to the further feature of the present invention, the highest number of repeated transmission of the frequency hopping packet of the first-affiliated unit is 2·6*, preferably It is 3 times. = 苐 - The auxiliary unit receives the acknowledgment packet sent by the first main unit in the repeated transmission of the synchronized hopping packet to the highest number of months 1j, and the first auxiliary unit can be switched to a second main unit. The above and other objects, features, and advantages of the present invention will become more apparent. U V* #implementation method]

8 ISS-P060010-TW 1337813

This is a good example of the invention, and is not intended to be an example of the invention, and is not intended to be limited to the core of the diagram or the specific description In the case of the second embodiment, the 1 series and the proposed mechanism according to the supervision bud standard can avoid the exchange angle map and fail to interfere or other factors. Please refer to the third example of the packet transmission process of the exchange role disclosed by the third invention. This mechanism is characterized by a mechanism for resending packets and automatically exchanging roles, y to effectively avoid the failure of the exchange role caused by the synchronization of the hopping packet or the confirmation of the packet in the original Bluetooth specification. In the definition of the k-bud system, the status of all devices is equal. In the original, any Bluetooth device can be the main unit or the slave unit. The only rule is to first ask for the connection. The device is called the main unit, and the connected device is called the slave unit. [The role assignment is determined when the network link is formed. Depending on the needs of the application, sometimes the functions of the main unit or the slave unit can be switched to each other. When two Bluetooth devices are connected to each other, it is equal to establishing a physical channel at the baseband level. The signal transmission between the main unit and the subsidiary unit in the physical channel is time-division multiplex (Time Division Duplex). , TDD) way. The main unit sends the data in the even slot (Time slot), and the auxiliary unit monitors. In the next time slot, the auxiliary unit sends the data and the main unit monitors.

9 ISS-P060010-TW 1337813 The action of exchanging characters starts with a first time ti, a first auxiliary unit 310 wants to convert the role into a main unit and sends a synchronized frequency hopping packet to a first main unit 320, the first A primary unit 320 sends back an acknowledgement packet. Even if the acknowledgment packet is not received by the accessory unit 310 due to interference or other factors, the first primary unit 320 has been switched to a second accessory unit 340 at a second time t2, at which time the original first accessory unit 310 The acknowledgment packet from the original primary unit is not received, and it is not known whether the original primary unit 320 received the same hopping packet. The original first accessory unit 310 then transmits the synchronized frequency hopping packet several times. At a third time t3, the first accessory unit 310 automatically switches to a second primary unit 330, thus avoiding a situation in which the role is lost when the role is exchanged. After the third time t3, after the primary unit/subsidiary unit is converted into the new auxiliary unit/new primary unit, a second polling packet is sent by the second primary unit 330, and the second auxiliary unit 340 receives the first After the second main unit 330 sends a polling packet, it sends an empty packet to the second φ main unit 330, thereby completing the action of the entire exchange role. After the first auxiliary unit 310 wants to convert the role into the primary unit and sends a synchronized hopping packet to the first primary unit 320, the method further includes the following steps: the first primary unit 320 sends a confirmation packet to the first An accessory unit 310. In general, the first time t1 is less than the second time t2, and the second time t2 is less than the third time t3. The third time t3 can be preset between 0.625ms and 20ms, preferably a multiple of 0.625ms. However, it should be noted that

10 ISS-P060010-TW 1337813 The third time t3 needs to be less than one exchange role time. The exchange role time is preferably 20ms. The maximum number of times the first accessory unit repeatedly transmits the synchronized frequency hopping packet is 2-6 times, preferably 3 times. If the first accessory unit receives the acknowledgement packet sent by the first primary unit before repeatedly transmitting the synchronized frequency hopping packet to the highest number of times, the first accessory unit 310 can switch to the second primary unit 330. The packets passed on the time slot do not occupy the entire time slot, and the Φ transmission time of each time slot is 625 ps, that is, the frequency is 1600 slots/sec. Since Bluetooth uses a frequency hopping mechanism, it will jump to another channel as it enters the next time slot. Bluetooth will cut the 2.45GHz communication band into 79 1MHz channels, and the data will be transmitted alternately on these 79 channels. The main unit only transmits data in even time slots. The auxiliary unit device only transmits data in odd time slots. The packets transmitted by the main unit not only occupy one time slot, but also extend to three or five time slots. Among them, the synchronous frequency hopping packet (FHS) is the same as the various packets in the other segments (synchronous φ link-oriented, SCO and asynchronous link-oriented, ACL link), and has three parts: access code, header and load. The acknowledgment packet (ID) consists only of the access code and is used during the pre-connection action. The acknowledgment packet is a powerful signal machine because it only carries access code information from where the device came from or where it is going. An empty (Null) packet consists only of an access code and a packet header, and the empty packet itself does not need to have a response to it. A polling packet has the same structure as an empty packet, but a polling packet must have a response message.

11 ISS-P060010-TW 1337813 In summary, according to the present invention, a character exchange method for Bluetooth wireless communication can reinforce the Bluetooth specification by a mechanism of resending packets and automatically exchanging roles. The weaker part avoids the failure of the exchange role when connecting, and avoids the situation that the connection is not connected to each other. And when users connect to each other's Bluetooth devices, both the linker and the connected person have more stability and can be satisfied. While the invention has been described in terms of the foregoing preferred embodiments, the invention may be modified and modified without departing from the spirit and scope of the invention. As explained above, various types of corrections and changes can be made without detracting from the spirit of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

12 ISS-P060010-TW f BRIEF DESCRIPTION OF THE DRAWINGS The objects, features, and advantages of the present invention are set forth in the accompanying drawings, and the preferred embodiments of the present invention. : The first picture of the success of the father's role change is shown in the schematic diagram of the transmission process of the conventional Bluetooth specification; the packet of the failure of the exchange role in the transmission bud specification is shown in Figure 3, which shows one of the packet transmission processes of the exchange role disclosed in the present invention. Example. [Main Element Symbol Description] 310 First Auxiliary Unit 320 First Main Unit 330 Second Main Unit 340 Second Subsidiary Unit

13 ISS-P060010-TW

Claims (1)

I33J813 X. Patent application scope: 1. A role exchange method for Bluetooth wireless communication. When a confirmation packet continues to transmit, the action of exchanging characters is automatically completed, which includes the following steps: At a first time 11 o'clock a first auxiliary unit that wants to convert the role and sends a synchronized frequency hopping packet to a first primary unit, and the first auxiliary unit transmits data only in an odd time slot; At a second time t2, the first primary unit switches to a second secondary unit, and transmits an acknowledgement packet to the first secondary unit, and the first primary unit transmits data only in an even number of time slots; If the auxiliary unit confirms that the packet reception fails, the synchronized frequency hopping packet is repeatedly transmitted multiple times; when the acknowledgment packet still fails to receive, at a third time t3, the first auxiliary unit is automatically switched to a second synchronization. a primary unit, and one of the best times of the third time is 20 ms and an optimal frequency is 1600 slots/sec; After the third time t3, a polling packet is sent by the second main unit, and the second main unit transmits data only in an even time slot, and when the second auxiliary unit receives the second main unit. After sending a polling packet, an empty packet is sent to the second main unit, and the second auxiliary unit transmits data only in an odd time slot. 2. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein after the first time 11, the following step 14 is further included: ISS-P060010-TW 1337813 Step: A first subsidiary unit requires exchange The role sends a synchronized hopping packet to a first primary unit; and the first primary unit sends an acknowledgment packet to the first secondary unit. 3. The role exchange mode for Bluetooth wireless communication according to item 1 of the patent application scope, wherein the third time t3 is between 0.62 5ms and 20ms. 4. The role exchange mode for Bluetooth wireless communication according to item 4 of the patent application scope, wherein the third time t3 is a multiple of 0.625 ms. 5. The role exchange method for Bluetooth wireless communication according to item 1 of the patent application scope, wherein the third time t3 needs to be less than one exchange role time. 6. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the first auxiliary unit repeatedly transmits the synchronized hopping packet 2 to 6 times. 7. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the first auxiliary unit receives the confirmation sent by the first primary unit before repeatedly transmitting the synchronized frequency hopping packet to the highest number of times The packet can be switched to the second main unit by the first auxiliary unit. 15 ISS-P060010-TW I3J7813 8. The role exchange method for Bluetooth wireless communication according to item 6 of the patent application scope, wherein the first auxiliary unit repeatedly transmits the synchronized hopping packet to the number of times preferably three times. 9. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the packet transmitted by the first main unit and the second main unit occupies 1 time slot, 3 time slots, and 5 time slots. One of the groups of the trough. 10. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the packet transmitted by the first main unit and the second main unit occupies one time slot. 11. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the packet transmitted by the first main unit and the second main unit occupies 3 time slots. 12. The role exchange method for Bluetooth wireless communication according to Item 1 of the patent application, wherein the packet transmitted by the first main unit and the second main unit occupies 5 time slots. 16 ISS-P060010-TW