CN105657811A

CN105657811A - Automatic synchronization method for ad hoc network nodes

Info

Publication number: CN105657811A
Application number: CN201410637358.5A
Authority: CN
Inventors: 郑银香
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-13
Filing date: 2014-11-13
Publication date: 2016-06-08

Abstract

The invention discloses relates to an automatic synchronization method for ad hoc network nodes. A node in a wireless ad hoc network system adjusts system timing thereof by calculating timing offsets with all adjacent nodes so as to synchronize with other nodes. The method is characterized in that all nodes in the system appoint the same timing, and a node periodically sends synchronization and broadcast signals within the appointed time slot of a frame structure and receives synchronization and broadcast signals of other nodes within the appointed sending time slot of the other nodes. The timing offsets between the current node and the other adjacent nodes are calculated, and the other adjacent nodes are notified via a timing broadcast channel. The node adjusts the system time thereof based on a weighted average algorithm according to the timing offsets with the other adjacent nodes so as to synchronize with the other nodes in the network. By adopting the method, all nodes can automatically synchronize by means of the design characteristics of the system in the wireless ad hoc network.

Description

Self-organizing network nodes automatic synchronous method

Technical field

The present invention relates to wireless communication field, be automatically performed, more particularly, to multinode physical layer in wireless self-networking, the method that timing synchronizes.

Background technology

Wireless self-networking is a kind of technology being different from conventional wireless communication network.

Traditional wireless cellular communication network, it is necessary to the fixing network equipment, such as the support of base station, carries out forwarding and user's Service controll of data. And wireless self-networking need not fix equipment support, the networking voluntarily of each node and user terminal. During communication, other user nodes carry out the forwarding of data. This latticed form breaches the geographic limitations of conventional wireless cellular network, it is possible to quicker, convenient, dispose efficiently, is suitable for the communication needs of some urgent occasions, such as individual soldier's communication system etc. in battlefield. But wireless self-networking there is also, and the network bandwidth is limited, real-time service is supported the drawback poor, safety is not high. At present, a large amount of research worker is had to carry out this project research both at home and abroad.

Wireless self-networking is one and is formed by tens to up to a hundred nodes, adopted communication, the mobility peer-to-peer network of the multi-hop of dynamic group net. Its objective is the multimedia information stream by dynamic routing and mobile management technical transmission with quality of service requirement.

Wireless self-networking is based on the Wireless Broadband MAN of IP agreement, support multi-multipoint network structure, there is intelligence advantage and the features such as mobile broadband, wireless location such as MANET, selfreparing, multi-hop cascade, node self management, it is the network of a kind of Large Copacity, two-forty, wide coverage, becomes a kind of effective means of broadband access. Saying in a sense, wireless self-networking is a kind of network architecture thought, and major function is embodied in non-stop layer, MANET, multistage jumper connection and route and judges selection etc.

Wireless self-networking is a kind of and the diverse new wireless networks technology of conventional wireless network. In traditional WLAN (WLAN), each client accesses network each through a wireless link being connected with access point (AP), user is to intercom mutually, it is necessary to first accessing a fixing AP, this network structure is called single-hop networks. And in wireless self-networking, any wireless device node all can simultaneously as router, each node in network can send and receive signal, and each node directly can communicate with one or more peer node.

The largest benefit of this structure is in that: if nearest AP is excessive and cause congested due to flow, data can be automatically rerouted to a less adjacent node of communication flows and be transmitted.The rest may be inferred, and packet according to the situation of network, can also continue to route to next node nearest with it and be transmitted, until arriving final destination. Such access mode is exactly that multi-hop accesses.

The Internet (Internet) that we know in fact is exactly the exemplary of a wireless self-networking. When we send a Email, mail is not directly arrive in the mailbox of addressee, but is forwarded to another one server by router from a server, just arrives the mailbox of user through repeatedly routing forwarding. In repeating process, router generally understands the transmission path that efficiency of selection is the highest, in order to make Email can arrive the mailbox of user as early as possible. Therefore, wireless self-networking can regard " wireless version of the Internet " as.

Summary of the invention

The wireless self-organizing network nodes automatic synchronous method that the present invention relates to, it is possible under the scene not relying on external system timing source, it is achieved all node automatic synchronizations in system.

According to an aspect of the present invention, a kind of wireless self-networking physical layer synchronization method contains following steps successively:

In engagement system, all nodes have identical timing, and each node has independent synchronization and broadcast message sending time slots,

Step (1) system has periodic frame structure

In described wireless self-networking, system has periodic frame structure, and each cycle internal information array format is identical;

Step (2) node periodically sends and synchronizes and broadcast singal

In described wireless self-networking, all nodes send in its agreement time slot periodically and synchronize and broadcast singal;

Other node of step (3) node periodic receipt synchronizes and broadcast singal

In described wireless self-networking, all nodes receive synchronization and the broadcast singal of all neighbors about in agreement time slot periodically;

Step (4) broadcast timing offset information

In described wireless self-networking, all nodes broadcast the timing offset information of its around all neighbors all with it calculated according to self timing ga(u)ge by its period of broadcast channel;

Step (5) adjusts timing point

The timing offset information relevant to himself that in described wireless self-networking, all nodes are broadcasted according to all neighbors, and the timing offset information with all neighbors around self calculated, it is weighted by average algorithm and calculates timing adjustment values, adjust timing deviation.

According to a further aspect in the invention, described wireless self-networking is when arranging the timing of all nodes and being consistent, utilize the timing offset information that all neighbors calculate about, and the timing offset information with all neighbors around self calculated, it is weighted by average algorithm computing system timing adjustment values.

Accompanying drawing explanation

Fig. 1 represents that when wireless self-organizing network nodes of the present invention timing is consistent, propagation delay time calculates schematic diagram.

Fig. 2 represents that when wireless self-organizing network nodes of the present invention timing is inconsistent, propagation delay time calculates schematic diagram.

Fig. 3 represents wireless self-networking frame structure schematic diagram of the present invention.

Detailed description of the invention

In order to reach the purpose of the present invention, by the following technical solutions:

(1) arrange all nodes in described wireless self-networking and there is identical timing.

(2) in described wireless self-networking, all nodes are according to the timing of oneself in its agreement time slot, and periodically transmission synchronizes and broadcast singal, as shown in Figure 3. Each node has the transmission position that it is independent, does not conflict mutually.

(3) in described wireless self-networking, all nodes receive synchronization and the broadcast singal of other all neighbors in the agreement time slot of other node, and calculate its time deviation according to the timing of oneself. Hereinafter illustrate in two kinds of situation:

(a) when all nodes timing consistent, as shown in Figure 1.Node 1 and node 2 send according to accurate timing in its agreement time slot and synchronize and broadcast singal, and carry out synchronizing and broadcast signal reception at the sending time slots of other node. Now, the path delay of time 1 and the path delay of time 2 of node 1 calculating that node 2 calculates are essentially equal, and are directly proportional to the distance between two nodes.

B (), when there is timing offset, node timing occurs inconsistent, as shown in Figure 2. Node 1 sends according to timing in advance in its time slot and synchronizes and broadcast singal, and the synchronization sent at the sending time slots receiving node 2 of node 2 and broadcast singal, now, timing advance due to node 1, the path delay of time 1 that node 2 calculates diminishes, and the path delay of time 2 that node 1 calculates becomes big, the path delay of time, distance and the timing offset with two nodes had relation.

(4) path delay of time information relevant to himself that described wireless self-networking interior nodes is broadcasted according to all neighbors, and the information in the path delay of time with all neighbors around self calculated, calculate timing adjustment values by certain algorithm, adjust the timing deviation of oneself.

Being more than physical layer Timing Synchronization computational methods example in a wireless self-networking, any utilization is just sent out all at this patent protection domain described in accompanying drawing 1-3.

Claims

1. a self-organizing network nodes automatic synchronous method, described method contains following steps successively:

Step (1) system has periodic frame structure

Step (2) node periodically sends and synchronizes and broadcast singal

Other node of step (3) node periodic receipt synchronizes and broadcast singal

Step (4) broadcast timing offset information

Step (5) adjusts timing point

2. a kind of wireless self-organizing network nodes automatic synchronous method according to claim 1, it is characterized in that: described wireless self-networking is when arranging the timing of all nodes and being consistent, utilize the timing offset information that all neighbors calculate about, and the timing offset information with all neighbors around self calculated, it is weighted by average algorithm computing system timing adjustment values.