CN102665268B - Distributed time synchronization method for hierarchical clustering wireless self-organized network - Google Patents

Abstract

The invention discloses a distributed time synchronization method for a hierarchical clustering wireless self-organized network. The method includes: decomposing time synchronization of the self-organized network into time synchronization of a plurality of sub-networks with overlaid nodes by means of a controllable feature of a TDMA (time division multiple access) frame structure access mode, and stepwise establishing sub-network internal collaborative times so as to complete time synchronization of the self-organized network, wherein the time synchronization of the sub-networks includes coarse time synchronization and precision time synchronization, the coarse time synchronization is completed by the aid of a cluster head broadcast-cluster member response mode, and the precision time synchronization is established by adopting a handshake protocol and establishing the collaborative times by means of collaborative operation through continuous synchronous application and based on parallel application and distributed computation, calibration and updating of the collaborative times. The method is high in adaptability, the demands on computation and storage capacity of nodes in the self-organized network are low, computing resources of each node are fully used, extra channel resources in time synchronization are not needed, and time for realizing global synchronization of the self-organized network is short.

Description

A kind of distributed clock synchronous method of classification cluster wireless self-organizing network

Technical field

The invention belongs to wireless network clock synchronous field, more particularly, is a kind of distributed clock synchronous method of the classification cluster wireless self-organizing network based on without high-accuracy standard time clock time service.

Background technology

Significant progress has been experienced in radio network technique and application, especially in self-organizing network field.Physically, the node geographically distributing that wireless self-organization network comprises some, the infrastructure that participates in networking is no longer fixing, and uses shared wireless channel.In application, the field that wireless self-networking relates to is very extensive, comprises WLAN (wireless local area network), emergency communication net and military combat communication network etc.

In the application of wireless self-networking, especially, in information and the free application relying on of transmission, also improve for the clock synchronous demand of network thereupon.

In wireless self-organization network synchronization mechanism, have two kinds of main methods, i.e. the method for satellite synchronization time service and certain nodal clock of setting are the method in reference clock source.The method of satellite synchronization time service is to resolve by synchronous satellite time service based on high accuracy atomic clock, make all self-organizing network interior nodes all obtain the accurate moment, and revise, thereby it is synchronous to complete network global clock.The method of setting certain nodal clock and be reference clock source is in network, to select clock that precision is higher as reference clock, then carry out regular synchronized broadcasting and set up clock synchronous end to end, all nodes all rerun, and this forms clock synchronization of ad after clock synchronous end to end.

Method based on satellite synchronization time service has that accuracy is high, retaining zone advantage widely.But there are two prerequisites, the one, there is available synchronous time service satellite, this is at some interference environment or cover under environment and cannot realize; The 2nd, synchronization node need to be installed satellite synchronization resolver, and the node that reception resolver is not installed cannot participate in synchronously.

Set in the method that certain nodal clock is reference clock source, by adopting PTP (Precision Time Protocol, translation: precision clock agreement) agreement can realize clock synchronous end to end, and all net interior nodes all adopt that can to realize the global clock of network after this agreement synchronous.But its shortcoming clearly, while breaking down and damage in reference clock source, clock synchronous cannot carry out, and this can directly cause network failure; Secondly, repeatedly carrying out end-to-end clock synchronization protocol in the situation that number of network node is more, need to expend long time, is unhelpful for the self-organizing network with dynamic characteristic; Finally, for the network with classification, the clock synchronous end to end of carrying out an inter-stage just need to take for a long time, can affect the normal operation of network.

Summary of the invention

For improving the survivability of clock synchronization of ad, reduce the required time of Network Synchronization, strengthen the continuity of system applies, the present invention proposes a kind of distributed clock synchronous method of classification cluster wireless self-organizing network.

The distributed clock synchronous method of a kind of classification cluster wireless self-organizing network of the present invention, described classification cluster wireless self-organizing network is secondary classification cluster wireless ad-hoc network, multiple sub-networks are divided into primary network station and two grade network by classification line; Two grade network communicates by gateway link and primary network station; In each sub-network, include cluster head node and bunch member node; The clock synchronous of described classification cluster wireless self-organizing network comprises following treatment step:

Step 1: after the whole network initialization starts, carry out the collaborative clock synchronous strategy of subnet in primary network station net; Meanwhile, in two grade network net, carry out the collaborative clock synchronous strategy of subnet;

Step 2: complete after clock synchronous in primary network station net, need to judge in subnet at the corresponding levels whether also have the application of one-level clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes primary network station; If nothing, the each node of primary network station is synchronously applied for to gateway link tranmitting data register;

In two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether also have the application of secondary clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network;

Step 3: gateway link is carried out the collaborative clock synchronous strategy of subnet;

Step 4: complete after clock synchronous in chains of gateways road network, need to judge in subnet at the corresponding levels whether also have the application of gateway clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes gateway link; If nothing, the family of the each node of primary network station by chains of gateways road direction two grade network is starting send family first clock synchronous application;

Step 5: again carry out the collaborative clock synchronous strategy of subnet according to the first clock synchronous application of family in two grade network net, in two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether to also have the application of secondary clock synchronous according to the receipt message in mini-slot, if have, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network; If nothing, the whole network reaches clock synchronous, and the clock synchronous process of the whole network finishes.

The distributed clock synchronous method of a kind of classification cluster wireless self-organizing network of the present invention, the collaborative clock synchronous strategy of its subnet includes thick clock synchronous and two stages of smart clock synchronous; After the collaborative clock synchronous of subnet starts, first carry out subnet broadcast formula synchronous, cluster head sends synchronised clock, and a bunch member completes and replys after refresh clock; Subnet broadcast formula has judged whether smart clock synchronous application after with EOS, if having, proceeds to and carries out subnet to reply formula synchronous; If nothing, thick clock synchronous finishes.Synchronously, adopt collaborative clock mode to continue to have judged whether smart clock synchronous request in the subnet formula of replying, if having, it is synchronous that continuation execution subnet is replied formula; If nothing, smart clock synchronous finishes.

The advantage of distributed clock synchronous method of the present invention is:

1. carry out clock synchronous process time without selection reference clock end, only pay close attention to the topological structure of the wireless self-organization network of whole classification sub-clustering, there is very strong adaptability.

2. in clock synchronous process, take full advantage of the computational resource of each node in the wireless self-organization network of all classification sub-clusterings, reduced the collaborative calculating of clock end and the demand of storage capacity.

3. this method improves the survivability of Network Synchronization clock, even after extreme dynamic network or node variation, need building network again, adopts the method also can realize the synchronous again of network.

Brief description of the drawings

Fig. 1 is the classification cluster wireless ad-hoc network schematic diagram with secondary structure.

Fig. 2 is tdma frame structure chart.

Fig. 3 is the flow chart of classification cluster wireless self-organizing network clock synchronous of the present invention.

Fig. 4 is the clock synchronous flow chart of each sub-network of the present invention.

Fig. 5 is broadcast-acknowledge synchronization process sketch of classification cluster wireless self-organizing network of the present invention.

Fig. 6 is that the present invention records available moment data procedures schematic diagram.

Fig. 7 is the end-to-end Handshake Protocol process moment schematic diagram of the present invention's essence clock synchronous.

1. first sub-network	11. first network nodes	12. second network nodes	13. the 3rd network nodes
				14. the 4th network nodes	15. the 5th network nodes	2. second sub-network	21. the 6th network nodes
22. the 7th network nodes	23. the 8th network nodes	3. the 3rd sub-network	31. the 9th network nodes
				32. the tenth network nodes	33. the 11 network nodes	34. the 12 network nodes	4. the 4th sub-network
41. the 13 network nodes	42. the 14 network nodes	43. the 15 network nodes	44. the 16 network nodes
				5. the 5th sub-network	51. the 17 network nodes	52. the 18 network nodes	53. the 19 network nodes
54. the 20 network nodes	1-2. the first gateway link	1-3. the second gateway link	1-4. the 3rd gateway link
				1-5. the 4th gateway link	201. start guiding time slot	202. transfer of data time slots	203. mini-slot

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further detail.

Shown in Figure 1, in figure, show a typical secondary classification cluster wireless ad-hoc network, multiple sub-networks are divided into primary network station and two grade network by classification line; In each sub-network, include cluster head node and bunch member node; Described sub-network includes the first sub-network 1, the second sub-network 2, the 3rd sub-network 3, the 4th sub-network 4, the 5th sub-network 5; The first sub-network 1 belongs to primary network station; The second sub-network 2, the 3rd sub-network 3, the 4th sub-network 4, the 5th sub-network 5 belong to two grade network.

In the first sub-network 1, include first network node 11, second network node 12, the 3rd network node 13, the 4th network node 14 and the 5th network node 15, first network node 11 is the cluster head node in the first sub-network 1, and all the other four nodes (being second network node 12, the 3rd network node 13, the 4th network node 14 and the 5th network node 15) are bunch member node in the first sub-network 1.

In the second sub-network 2, include the 6th network node 21, the 7th network node 22 and the 8th network node 23, the 6th network node 21 is the cluster head node in the second sub-network 2, and all the other two nodes (i.e. the 7th network node 22 and the 8th network node 23) are bunch member node in the second sub-network 2.

In the 3rd sub-network 3, include the 9th network node 31, the tenth network node the 32, the 11 network node the 33 and the 12 network node 34, the 9th network node 31 is the cluster head node in the 3rd sub-network 3, and its excess-three node (i.e. the tenth network node the 32, the 11 network node the 33 and the 12 network node 34) is bunch member node in the 3rd sub-network 3.

In the 4th sub-network 4, include the 13 network node the 41, the 14 network node the 42, the 15 network node the 43 and the 16 network node 44, the 13 network node 41 is the cluster head node in the 4th sub-network 4, and its excess-three node (i.e. the 14 network node the 42, the 15 network node the 43 and the 16 network node 44) is bunch member node in the 4th sub-network 4.

In the 5th sub-network 5, include the 17 network node the 51, the 18 network node the 52, the 19 network node the 53 and the 20 network node 54, the 17 network node 51 is the cluster head node in the 5th sub-network 5, and its excess-three node (i.e. the 18 network node the 52, the 19 network node the 53 and the 20 network node 54) is bunch member node in the 5th sub-network 5.For example, the first sub-network 1 adopts identifier AA to represent, the cluster head in the first sub-network 1 adopts AA ^m, any one bunch of member in the first sub-network 1 adopts AA _a, adopt set form to be expressed as AA={AA for cluster head, a bunch member in the first sub-network 1 ^m, AA ₁, AA ₂..., AA _a.In like manner, in the second sub-network 2, cluster head, a bunch member adopt set form to be expressed as BB={BB ^m, BB ₁, BB ₂..., BB _b.In the 3rd sub-network 3, cluster head, a bunch member adopt set form to be expressed as CC={CC ^m, CC ₁, CC ₂..., CC _c.In the 4th sub-network 4, cluster head, a bunch member adopt set form to be expressed as DD={DD ^m, DD ₁, DD ₂..., DD _d.In the 5th sub-network 5, cluster head, a bunch member adopt set form to be expressed as EE={EE ^m, EE ₁, EE ₂..., EE _e.

In the classification cluster wireless ad-hoc network of typical secondary structure as shown in Figure 1, two grade network communicates by gateway link and primary network station, be that second network node 12 is the first gateway link 1-2 with communicating by letter of the 6th network node 21, first network node 11 is the second gateway link 1-3 with communicating by letter of the 9th network node 31, the 5th network node 15 is the 3rd gateway link 1-4 with communicating by letter of the 13 network node 41, and the 4th network node 14 is the 4th gateway link 1-5 with communicating by letter of the 17 network node 51.In the present invention, gateway link is the sub-network of two nodes, is taking the node in the first sub-network 1 as cluster head, is taking cluster head node in the second sub-network 2, the 3rd sub-network 3, the 4th sub-network 4 and the 5th sub-network 5 as a bunch member.Node on gateway link is also referred to as gateway node.Therefore, gateway link is the sub-network of two nodes, is taking the node in primary network station as cluster head, is taking the cluster head node in two grade network as a bunch member.In gateway link, cluster head, a bunch member adopt set form to be expressed as FF={FF ^m, FF ₁, FF ₂..., FF _f.

In the present invention, subnet is worked in coordination with clock synchronous application of policies cluster head, bunch member carries out moment record for identity, and therefore, in different sub-networks, cluster head, a bunch member adopt different identification to meet and identify.For example, the cluster head in primary network station, a bunch member adopt a kind of mark to meet; Cluster head in two grade network, a bunch member adopt another kind of mark to meet; Cluster head in gateway link, a bunch member adopt the third mark to meet.Under different marks meets, the moment record required for the collaborative clock synchronous of subnet also meets with this mark.

For ensureing the controllability of transfer of data in classification cluster wireless ad-hoc network, reduce transmission collision, the access of each sub-network and transmission adopt tdma frame structure, as shown in Figure 2, tdma frame comprises startup guiding time slot 201 and transfer of data time slot 202, comprises limited mini-slot 203 in each time slot.Start access, resource bid and the clock synchronous of guiding time slot 201 for network, transfer of data time slot 202 is for transmitting Various types of data.TDMA, Time Division Multiple Access, translation is time division multiple access.Time division multiple access is to become each frame of periodic frame (Frame) to be divided into several time slots to base station transmitted signal time division again, under regularly satisfied and synchronous condition, base station can receive respectively the signal of each mobile terminal and not mix and disturb in each time slot.Meanwhile, the signal that base station is sent to multiple mobile terminals is all arranged in order in predetermined time slot and transmits, and each mobile terminal as long as receive in the time slot of specifying, and in the signal on Jiu Nenghe road, handle is issued its signal distinguishing and receives.

For realizing the synchronous of whole classification cluster wireless self-organizing network, the transmission of classification cluster wireless MANET is decomposed into the process that gateway link transmission connects noiseless sub-network transmission, and clock synchronous flow process as shown in Figure 3 for the whole network (being classification cluster wireless self-organizing network).

Step 1: after the whole network initialization starts, carry out the collaborative clock synchronous strategy of subnet in primary network station net; Meanwhile, in two grade network net, carry out the collaborative clock synchronous strategy of subnet;

Step 2: complete after clock synchronous in primary network station net, need to judge in subnet at the corresponding levels whether also have the application of one-level clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes primary network station; If nothing, the each node of primary network station is synchronously applied for to gateway link tranmitting data register;

In two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether also have the application of secondary clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network;

Step 3: gateway link is carried out the collaborative clock synchronous strategy of subnet;

Step 4: complete after clock synchronous in chains of gateways road network, need to judge in subnet at the corresponding levels whether also have the application of gateway clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes gateway link; If nothing, the family of the each node of primary network station by chains of gateways road direction two grade network be starting send clock synchronous application (being called for short the first clock synchronous application of family);

Step 5: again carry out the collaborative clock synchronous strategy of subnet according to the first clock synchronous application of family in two grade network net, in two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether to also have the application of secondary clock synchronous according to the receipt message in mini-slot, if have, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network; If nothing, the whole network reaches clock synchronous, and the clock synchronous process of the whole network finishes.

Shown in Figure 4, in the present invention, the collaborative clock synchronous strategy of subnet includes thick clock synchronous and two stages of smart clock synchronous.After the collaborative clock synchronous of subnet starts, first carry out subnet broadcast formula synchronous, cluster head sends synchronised clock, and a bunch member completes and replys after refresh clock; Subnet broadcast formula has judged whether smart clock synchronous application after with EOS, if having, proceeds to and carries out subnet to reply formula synchronous; If nothing, thick clock synchronous finishes.Synchronously, adopt collaborative clock mode to continue to have judged whether smart clock synchronous request in the subnet formula of replying, if having, it is synchronous that continuation execution subnet is replied formula; If nothing, smart clock synchronous finishes.Thick clock synchronous process adopts broadcast reference clock mode, and smart clock synchronous process adopts collaborative clock mode.

(1) the thick clock synchronous stage

In the present invention, described thick clock synchronous adopts broadcast-answer-mode, as shown in Figure 5, comprises cluster head broadcast synchronization clock step and clock step is replied in bunch member's renewal.Wherein, cluster head broadcast synchronization clock step is to have after new node access with cluster head, starts self current clock of guiding time slot 201 periodic broadcasting, and this clock is designated as broadcast reference clock MT _current, treat that bunch member receives the broadcast reference clock MT described in this _currentafter, and the clock of renewal bunch member's startup guiding time slot 201, this clock is designated as follows clock S-MT _upgrade; Bunch member upgrades that to reply clock step be to complete the described clock S-MT that follows with bunch member _upgradesynchronous is MT _currentafter clock, and in bunch member's available mini-slot 203, start guiding time slot 201, and send syn ack, the thick clock synchronous process between so far cluster head-bunch member completes.

In the present invention, thick clock synchronous process comprises SYNC_T and two types of synchronous protocol information of SYNC_RES.Described SYNC_T refers to the synchronizing information (referred to as broadcast message) of cluster head broadcast, and this broadcast message at least includes broadcast reference clock.Described SYNC_RES refers to bunch member's response message, is replying as the result that cluster head synchronised clock is upgraded.SYNC_RES only comprises thick clock synchronous response message, does not comprise timestamp.

(2) the smart clock synchronous stage

Shown in Fig. 6, Fig. 7, after the thick clock synchronous between cluster head-bunch member completes, start smart clock synchronous process, smart clock synchronous comprises the following steps:

Step 61: record available moment data

In point fraction family wireless ad hoc network as shown in Figure 1, in order to realize cluster head and bunch member's collaborative clock synchronous, definition cluster head node is collaborative clock end N _co, definition bunch member node synchronously applies for holding N _do.For the subnet that has K bunch member node (also referred to as synchronous application end number) and 1 cluster head node, it is N that synchronous application end adopts set expression-form _do={ N ₁, N ₂..., N _k, N ₁represent the 1st synchronous application end, N ₂represent the 2nd synchronous application end, N _krepresent K synchronous application end, also referred to as any one synchronous application end; The smart clock synchronous of network refers to that any one node just initiates smart clock synchronous solicited message SYNC_PT and reference clock information FOLLOW_UP when time slot 201 starting guiding, as shown in Figure 7.SYNC_PT refers to that the synchronous application end of essence sends to the synchronization request information of collaborative clock end.FOLLOW_UP refers to that application end sends to the information of collaborative clock end, and logging timestamp in the time that the synchronous application of each essence SYNC_PT sends, is designated as the reference time of initiating application, and follows SYNC_PT and send.

Lost efficacy for preventing that loss that the time variation due to channel in wireless transmission may cause starting SYNC_PT, FOLLOW_UP that guiding time slot 201 transmits from causing to calculate, for collaborative clock end N _coit is invalid that the corresponding mini-slot in corresponding data frame does not receive SYNC_PT, FOLLOW_UP information is considered as synchronous application, and all record data in this frame are removed, until collaborative clock end N _cocorrectly receive synchronous request for data, and record frame number corresponding to described synchronous request for data.

In the present invention, the synchronous application end of record N _do={ N ₁, N ₂..., N _ksend moment matrix format and be $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right],$ represent the 1st synchronous application end N ₁the 1st the application delivery time sending, represent the 1st synchronous application end N ₁the 2nd the application delivery time sending, represent the 1st synchronous application end N ₁j the application delivery time sending is (also referred to as the 1st synchronous application end N ₁any one the application delivery time sending), represent the 2nd synchronous application end N ₂the 1st the application delivery time sending, represent the 2nd synchronous application end N ₂the 2nd the application delivery time sending, represent the 2nd synchronous application end N ₂j the application delivery time sending is (also referred to as the 2nd synchronous application end N ₂any one the application delivery time sending), represent any one synchronous application end N _kthe 1st the application delivery time sending, represent any one synchronous application end N _kthe 2nd the application delivery time sending, represent any one synchronous application end N _kj the application delivery time sending is (also referred to as any one synchronous application end N _kany one application delivery time sending).

In the present invention, collaborative clock end N _cothe time of reception, matrix format was $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right],$ represent collaborative clock end N _cothe 1st the synchronous application end N receiving ₁moment in the 1st synchronous application moment, represent collaborative clock end N _cothe 1st the synchronous application end N receiving ₁moment in the 2nd synchronous application moment, represent collaborative clock end N _cothe 1st the synchronous application end N receiving ₁moment in synchronous application moment of j (also referred to as collaborative clock end N _cothe 1st the synchronous application end N receiving ₁moment in any one synchronous application moment), represent collaborative clock end N _cothe 2nd the synchronous application end N receiving ₂moment in the 1st synchronous application moment, represent collaborative clock end N _cothe 2nd the synchronous application end N receiving ₂moment in the 2nd synchronous application moment, represent collaborative clock end N _cothe 2nd the synchronous application end N receiving ₂moment in synchronous application moment of j (also referred to as collaborative clock end N _cothe 2nd the synchronous application end N receiving ₂moment in any one synchronous application moment), represent collaborative clock end N _cothe K receiving a synchronous application end N _kmoment in the 1st synchronous application moment, represent collaborative clock end N _cothe K receiving a synchronous application end N _kmoment in the 2nd synchronous application moment, represent collaborative clock end N _cothe K receiving a synchronous application end N _kmoment in synchronous application moment of K (also referred to as collaborative clock end N _cothe K receiving a synchronous application end N _kmoment in any one synchronous application moment).

In the present invention, if collaborative clock end N _cothe corresponding mini-slot in corresponding data frame does not receive SYNC_PT, FOLLOW_UP information, is considered as that synchronous application is invalid is designated as 0.For example,, as collaborative clock end N _codo not receive the 2nd synchronous application end N the 1st synchronous application moment ₂sYNC_PT, FOLLOW_UP information, collaborative clock end N _cothe time of reception, matrix format was $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ 0& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right],$ Collaborative clock end N _cothe 2nd column data in sweeping matrix.

Step 62: select collaborative function

The collaborative function f () of definition, within its objective is one group of data being converged to an acceptable scope gradually, and can not change the attribute of data in application process, every execution is this functional operation once, there is certain compression function for the data of disperseing.In the present invention, collaborative function form is the moment $\mathrm{COLK}=\left\{\begin{array}{c}f(x_1,x_2,...,x_K)={\mathrm{\ω}}_1{x}_1+{\mathrm{\ω}}_2{x}_2+\·\·\·+{\mathrm{\ω}}_K{x}_K\\ \underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{\ω}}_i=1\end{array}\right.,$ ω _krepresent any one synchronous application end N _kweighted value, ω ₁represent first synchronous application end N ₁weighted value, ω ₂represent second synchronous application end N ₂weighted value, x _krepresent collaborative clock end N _coany one the synchronous application end N receiving _knon-zero synchronously apply for moment (referred to as effective moment in synchronous application moment) in moment, x ₁represent collaborative clock end N _cofirst the synchronous application end N receiving ₁moment in effectively synchronous application moment, x ₂represent collaborative clock end N _cosecond the synchronous application end N receiving ₂moment in effectively synchronous application moment, K represents the number of synchronous application end, ω _ithe index corresponding with choosing synchronous application end i in expression and relation.

In the present invention, adopt $\mathrm{COLK}=\left\{\begin{array}{c}f(x_1,x_2,...,x_K)={\mathrm{\ω}}_1{x}_1+{\mathrm{\ω}}_2{x}_2+\·\·\·+{\mathrm{\ω}}_K{x}_K\\ \underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{\ω}}_i=1\end{array}\right.$ Right $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Carry out moment convergence and obtain collaborative clock end N _co(collaborative clock end N _cofor the moment receiving) effectively collaborative moment function.

In the present invention, adopt $\mathrm{COLK}=\left\{\begin{array}{c}f(x_1,x_2,...,x_K)={\mathrm{\ω}}_1{x}_1+{\mathrm{\ω}}_2{x}_2+\·\·\·+{\mathrm{\ω}}_K{x}_K\\ \underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{\ω}}_i=1\end{array}\right.,$ $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right]$ Carry out moment convergence and obtain synchronous application end N _do={ N ₁, N ₂..., N _k(synchronous application end N _do={ N ₁, N ₂..., N _kbe moment of sending) effectively collaborative moment function.

In the present invention, synchronous application end N _do={ N ₁, N ₂..., N _keffectively collaborative moment function also may equal $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right],$ Send the moment application in the time working in coordination with the poor calculating of clock time of reception in order to maximize statistics $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right]$ Calculate.In like manner can obtain collaborative clock end N _coeffectively collaborative moment function also may equal $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right],$ The moment receiving in order to maximize statistics, application in the time working in coordination with the poor calculating of clock time of reception $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Calculate.

Step 63: calculate collaborative clock time of reception poor

In the present invention, from $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ In choose effective two column elements, $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Be replaced into ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right],$ Right ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Carrying out transposition is ${\mathrm{TCT}}_{\mathrm{Re}}^{\mathrm{CO}}={\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]}^T.$ Choose $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right]$ In corresponding to ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Row, be replaced into ${\mathrm{CT}}_{\mathrm{Tr}}=\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right],$ Right ${\mathrm{CT}}_{\mathrm{Tr}}=\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right]$ Carrying out transposition is ${\mathrm{TCT}}_{\mathrm{Tr}}={\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right]}^T.$

Calculate the time difference from transmitting terminal clock to receiving terminal clock relative time clock drift is t _dR=Row (Δ T, j)-Row (Δ T, 1), Row (Δ T, j) represents the 2nd row element in Δ T, Row (Δ T, 1) represents the 1st row element in Δ T.Calculate the collaborative drift t of all nodal clocks in subnet _{cO, DR}=f (t _dR), in calculating subnet, collaborative clock receives the time difference of two groups of applications $t_{\mathrm{CO},\mathrm{DIST}}=f(\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}},j)-\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}},1))-t_{\mathrm{CO},\mathrm{DR}}.$

Step 64: revise gateway node clock for collaborative clock

Calculate the drift rate t of gateway node clock with respect to collaborative clock _{cD, DR}/ t _{cD, DIST}, and from this moment gateway node clock is modified to collaborative clock 605.

In Network Synchronization process, according to the end-to-end synchronous protocol of shaking hands (as shown in Figure 6, Figure 7) of design, application node continues in a frame, all applications to be sent to collaborative clock end, collaborative clock end records respectively the time of advent of application, after certain delay, send collaborative clock end and reply, content comprises clock drift rate and message time stamp content, and finally the each node in collaborative clock end carries out respectively clock correction 606 receiving after response message.Shown in Figure 7, shake hands in synchronous protocol end-to-end, the synchronous application end of essence need to obtain the application delivery time T0 of collaborative clock end, synchronously apply for that termination receives that collaborative clock end is replied the moment T3 of association, collaborative clock termination receives essence synchronous application end request moment T1 and moment T2 is replied in transmission, finally calculates synchronous application end clock compensation τ according to ((T1-T0)-(T3-T2))/2 _o, i.e. τ _o=((T1-T0)-(T3-T2))/2.

Shake hands in synchronous protocol end-to-end, synchronously the shake hands protocol information of middle transmission of essence comprises tri-kinds of SYNC_PT, FOLLOW_UP and SYNC_CO.SYNC_CO refers to that collaborative clock end sends to the synchronised clock information of the synchronous application end of essence, as the response to net inter-sync application.SYNC_CO comprises and obtains the poor and frame number of collaborative time of receptions that collaborative clock stage continuous whole receives two synchronous applications, and sends the timestamp of this information.

In the present invention, smart clock synchronous process comprises to be obtained collaborative clock stage 601 and Network Synchronization stage 602, as shown in Figure 6.The collaborative clock stage 601 is the time differences that accurately receive the synchronous application of essence in order to obtain collaborative clock $t_{\mathrm{CO},\mathrm{DIST}}=f(\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}\left(2\right)},2)-\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}\left(2\right)},1))-t_{\mathrm{CO},\mathrm{DR}},$ The collaborative drift t of subnet interior nodes _{cO, DR}=f (t _dR) the drift rate t that work in coordination with clock relative to cluster head clock _{cD, DR}/ t _{cD, DIST}.The Network Synchronization stage 602 is the clock corrections in order to carry out any bunch of member.

The distributed synchronization method of the mobile Ad hoc network of classification sub-clustering of the present invention is utilized the controllable characteristics of TDMA access way, multiple subnets synchronous being synchronously decomposed into of network to coincidence node, completes the synchronous of network by setting up step by step the method for collaborative clock in subnet; The sync packet of subnet is containing thick synchronous and synchronous two processes of essence, the thick synchronous mode that adopts broadcast cluster head clock completes, the synchronous Handshake Protocol that adopts of essence, work in coordination with computing by continuous synchronous application and set up collaborative clock, carry out concurrent request, the foundation of Distributed Calculation calibration update mode synchronously based on collaborative clock.The method strong adaptability, the calculating to node and storage capacity demand are low, take full advantage of the computational resource of each node, when synchronous, without extra channel resource, realize synchronous required time short.

Claims (5)

1. a distributed clock synchronous method for classification cluster wireless self-organizing network, described classification cluster wireless self-organizing network is secondary classification cluster wireless ad-hoc network, multiple sub-networks are divided into primary network station and two grade network by classification line; Two grade network communicates by gateway link and primary network station; In each sub-network, include cluster head node and bunch member node; The clock synchronous that it is characterized in that described classification cluster wireless self-organizing network comprises following treatment step:

Step 1: after the whole network initialization starts, carry out the collaborative clock synchronous strategy of subnet in primary network station net; Meanwhile, in two grade network net, carry out the collaborative clock synchronous strategy of subnet;

Step 2: complete after clock synchronous in primary network station net, need to judge in subnet at the corresponding levels whether also have the application of one-level clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes primary network station; If nothing, the each node of primary network station is synchronously applied for to gateway link tranmitting data register;

In two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether also have the application of secondary clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network; When completing after clock synchronous in two grade network net, if judge in subnet at the corresponding levels there is no the application of secondary clock synchronous, finish the whole network synchronizing process;

Step 3: gateway link is carried out the collaborative clock synchronous strategy of subnet;

Step 4: complete after clock synchronous in chains of gateways road network, need to judge in subnet at the corresponding levels whether also have the application of gateway clock synchronous according to the receipt message in mini-slot, if having, return to the collaborative clock synchronous strategy of subnet that re-executes gateway link; If nothing, the family of the each node of primary network station by chains of gateways road direction two grade network is starting send family first clock synchronous application;

Step 5: again carry out the collaborative clock synchronous strategy of subnet according to the first clock synchronous application of family in two grade network net, in two grade network net, complete after clock synchronous, need to judge in subnet at the corresponding levels whether to also have the application of secondary clock synchronous according to the receipt message in mini-slot, if have, return to the collaborative clock synchronous strategy of subnet that re-executes two grade network; If nothing, the whole network reaches clock synchronous, and the clock synchronous process of the whole network finishes.

2. the distributed clock synchronous method of a kind of classification cluster wireless self-organizing network according to claim 1, is characterized in that: the collaborative clock synchronous strategy of described subnet includes thick clock synchronous and two stages of smart clock synchronous; After the collaborative clock synchronous of subnet starts, first carry out subnet broadcast formula synchronous, cluster head sends synchronised clock, and a bunch member completes and replys after refresh clock; Subnet broadcast formula has judged whether smart clock synchronous application after with EOS, if having, proceeds to and carries out subnet to reply formula synchronous; If nothing, thick clock synchronous finishes; Synchronously, adopt collaborative clock mode to continue to have judged whether smart clock synchronous request in the subnet formula of replying, if having, it is synchronous that continuation execution subnet is replied formula; If nothing, smart clock synchronous finishes.

3. the distributed clock synchronous method of a kind of classification cluster wireless self-organizing network according to claim 1, it is characterized in that: gateway link is the sub-network of two nodes, being taking the node in primary network station as cluster head, is taking the cluster head node in two grade network as a bunch member.

4. the distributed clock synchronous method of a kind of classification cluster wireless self-organizing network according to claim 2, it is characterized in that: described thick clock synchronous adopts broadcast-answer-mode, comprise cluster head broadcast synchronization clock step and clock step is replied in bunch member's renewal; Wherein, cluster head broadcast synchronization clock step is to have after new node access with cluster head, starts self current clock of guiding time slot periodic broadcasting, and this clock is designated as broadcast reference clock MT _current, treat that bunch member receives the broadcast reference clock MT described in this _currentafter, and the clock of renewal bunch member's startup guiding time slot, this clock is designated as follows clock S-MT _upgrade; Bunch member upgrades that to reply clock step be to complete the described clock S-MT that follows with bunch member _upgradesynchronous is MT _currentafter clock, and in bunch member's available mini-slot, start guiding time slot, and send syn ack, the thick clock synchronous process between so far cluster head-bunch member completes.

5. the distributed clock synchronous method of a kind of classification cluster wireless self-organizing network according to claim 2, it is characterized in that: after the thick clock synchronous between cluster head-bunch member completes, start smart clock synchronous process, smart clock synchronous comprises the following steps:

Step 61: record available moment data

For collaborative clock end N _coit is invalid that the corresponding mini-slot in corresponding data frame does not receive SYNC_PT, FOLLOW_UP information is considered as synchronous application, and all record data in this frame are removed, until collaborative clock end N _cocorrectly receive synchronous request for data, and record frame number corresponding to described synchronous request for data; The synchronous application end of record N _do={ N ₁, N ₂..., N _ksend moment matrix format and be $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right];$ Collaborative clock end N _cothe time of reception, matrix format was $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right];$

Step 62: select collaborative function

Moment, collaborative function form was $\mathrm{COLK}=\left\{\begin{array}{c}f(x_1,x_2,...,x_K)={\mathrm{\ω}}_1{x}_1+{\mathrm{\ω}}_2{x}_2+\·\·\·+{\mathrm{\ω}}_K{x}_K\\ \underset{i=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{\ω}}_i=1\end{array}\right.;$

Step 63: calculate collaborative clock time of reception poor

From $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ In choose effective two column elements, $T_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cccc}{t}_1^{\mathrm{CO},N1}& t_2^{\mathrm{CO},N1}& \·\·\·& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_2^{\mathrm{CO},N2}& \·\·\·& t_j^{\mathrm{CO},N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_2^{\mathrm{CO},\mathrm{NK}}& \·\·\·& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Be replaced into ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right],$ Right ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Carrying out transposition is ${\mathrm{TCT}}_{\mathrm{Re}}^{\mathrm{CO}}={\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]}^T;$ In like manner choose $T_{\mathrm{Tr}}=\left[\begin{array}{cccc}{t}_1^{N1}& t_2^{N1}& \·\·\·& t_j^{N1}\\ t_1^{N2}& t_2^{N2}& \·\·\·& t_j^{N2}\\ \·& \·& & \·\\ \·& \·& \·\·\·& \·\\ \·& \·& & \·\\ t_1^{\mathrm{NK}}& t_2^{\mathrm{NK}}& \·\·\·& t_j^{\mathrm{NK}}\end{array}\right]$ In corresponding to ${\mathrm{CT}}_{\mathrm{Re}}^{\mathrm{CO}}=\left[\begin{array}{cc}{t}_1^{\mathrm{CO},N1}& t_j^{\mathrm{CO},N1}\\ t_1^{\mathrm{CO},N2}& t_j^{\mathrm{CO},N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{CO},\mathrm{NK}}& t_j^{\mathrm{CO},\mathrm{NK}}\end{array}\right]$ Row, be replaced into ${\mathrm{CT}}_{\mathrm{Tr}}=\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right],$ Right ${\mathrm{CT}}_{\mathrm{Tr}}=\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right]$ Carrying out transposition is ${\mathrm{TCT}}_{\mathrm{Tr}}={\left[\begin{array}{cc}{t}_1^{N1}& t_j^{N1}\\ t_1^{N2}& t_j^{N2}\\ \·& \·\\ \·& \·\\ \·& \·\\ t_1^{\mathrm{NK}}& t_j^{\mathrm{NK}}\end{array}\right]}^T;$

Calculate the time difference from transmitting terminal clock to receiving terminal clock the relative time clock drift of calculating from transmitting terminal clock to receiving terminal clock is t _dR=Row (Δ T, j)-Row (Δ T, 1); Calculate the collaborative drift t of all nodal clocks in subnet _{cO, DR}=f (t _dR); In calculating subnet, collaborative clock receives the time difference of two groups of applications $t_{\mathrm{CO},\mathrm{DIST}}=f(\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}},j)-\mathrm{Row}(T_{\mathrm{Re}}^{\mathrm{CO}},1))-t_{\mathrm{CO},\mathrm{DR}};$ Row (Δ T, j) represents the 2nd row element in Δ T, and Row (Δ T, 1) represents the 1st row element in Δ T;

Step 64: revise gateway node clock for collaborative clock

Calculate the drift rate t of gateway node clock with respect to collaborative clock _{cD, DR}/ t _{cD, DIST}, and from this moment gateway node clock is modified to collaborative clock 605;

Each node in collaborative clock end carries out respectively clock correction 606 receiving after response message;

Shake hands in synchronous protocol end-to-end, the synchronous application end of essence need to obtain the application delivery time T0 of collaborative clock end, synchronously apply for that termination receives that collaborative clock end is replied the moment T3 of association, collaborative clock termination receives essence synchronous application end request moment T1 and moment T2 is replied in transmission, finally calculates synchronous application end clock compensation τ according to ((T1-T0)-(T3-T2))/2 _o.