CN115665768A - Hybrid channel allocation method suitable for wireless self-organizing network - Google Patents

Abstract

The invention relates to a mixed channel allocation method suitable for a wireless self-organizing network in the field of the wireless self-organizing network, in particular to a method suitable for a wireless self-organizing network environment adopting a Time Division Multiple Access (TDMA) mechanism. Firstly, a network cluster head node intensively allocates a special channel for a new network access node, so that the reliable transmission of time-sensitive services of each node can be ensured; meanwhile, considering that the special channel of each node has the characteristic of being spatially multiplexed by nodes other than two hops of the special channel, a mechanism for locally maintaining a shared channel list is designed, and a mechanism for reserving and competing on the special channel to occupy the shared channel is provided, so that collision caused by reservation message collision can be avoided, the information interaction times of competing the shared channel can be reduced, and the high-capacity data transmission requirement of each node is finally met. The mixed channel allocation method of the invention fully utilizes all channel resources of the network, is simple and easy to operate, and can effectively improve the transmission capability of the whole network.

Description

Hybrid channel allocation method suitable for wireless self-organizing network

Technical Field

The invention relates to a mixed channel allocation method suitable for a wireless self-organizing network in the field of wireless self-organizing networks, in particular to a method suitable for guaranteeing signaling and time-sensitive service transmission of each node in a centralized allocation dedicated channel mode in a wireless self-organizing network environment adopting a Time Division Multiple Access (TDMA) mechanism, improving the utilization rate of channel resources in a distributed competition shared channel mode and realizing reliable transmission of each node service in the network and overall improvement of the transmission capability of the whole network.

Background

The wireless self-organizing network is a wireless mobile communication network which is composed of a plurality of nodes with wireless transceiving functions and is free of infrastructure support. Because the transmission power of each node is limited, the transmission distance is limited, and when the nodes cannot directly communicate with each other, relay forwarding needs to be performed by other nodes in the network, so that the wireless ad hoc network is also a wireless multi-hop communication network. Because the wireless self-organizing network is not supported by infrastructures such as a base station, nodes in the network need signaling messages and service messages such as distributed interactive access control, a routing table, time synchronization and the like to complete networking and transmission; meanwhile, all nodes in the network share the wireless channel, and each node can obtain network access and channel resource use right according to a certain strategy.

In a wireless ad hoc network, how to allocate dedicated channel resources to each node while ensuring that the resource utilization of the entire network is maximized is a problem worthy of intensive research. Zhu et al, IEEE INFOCOM,1998, vol 1, 322-331: a five-phase reservation protocol (FPRP) for mobile ad hoc networks is provided, which can better adapt to topology change, but the channel sets of all node competition are the same, and the probability of competition conflict is higher. Masilamani et al, in Univ.of California,2012,1-6: a distributed time slot allocation mechanism based on the relative position virtual coordinates of nodes is provided in VCMA (virtual channel access in wireless mesh using virtual coordinates), information interaction and negotiation among the nodes can be reduced, but the method depends on a special public control channel existing in a system, and whole network paralysis can be caused once the special public control channel is interfered. Prihadi et al in APCC 2016, 535-540: an end-to-end connection-based channel allocation mechanism is provided in the A multi-channel MAC for multi-hop wireless sensor networks miniaturization and node convergence, which can improve a certain channel utilization rate, but in an actual wireless ad hoc network, a target node of service data of a node is unknown and variable before competing for channel resources and in a service transmission process, so that the applicability of the method is limited.

Disclosure of Invention

The invention aims to provide a hybrid channel allocation method suitable for a wireless self-organizing network. In a time synchronization TDMA network, a cluster head node intensively distributes dedicated channels for all other network access nodes, and low-delay and conflict-free transmission of time-sensitive services such as networking control signaling and short messages of each node is guaranteed; meanwhile, all nodes in the network reserve and occupy the shared channel in a distributed competition mode, the shared channel resources are fully utilized, and the data transmission capability of the whole network is improved.

The technical scheme adopted by the invention is as follows:

a hybrid channel allocation method suitable for a wireless ad hoc network comprises the following processes:

(1) After each wireless self-organizing node is started, monitoring 1 superframe period, if no time synchronization signal is heard, taking the wireless self-organizing node as a network cluster head node, and starting a network building process; if one or more time synchronization signals are intercepted, executing the step (2);

(2) The new startup node selects a node with the highest time synchronization signal level as a time synchronization reference node, initiates a network access request process, and allocates a dedicated channel for the new startup node by the cluster head node;

(3) In the network operation process, each node in the network independently maintains a shared channel list of the node, wherein the shared channel list comprises all common shared channels of the nodes in the network and a special shared channel of the node, and the special shared channel is the special channel of all other nodes outside the two-hop range of the node; when the service data quantity exceeds the capacity range, the shared channel is used in a competition mode in a reservation mode.

Wherein, the step (2) comprises the following steps:

(201) The newly started node analyzes all the sensed time synchronization signals to obtain the node ID, the time synchronization level, the total number of the nodes in the network, the ID list of the nodes in the network and the ID information of the cluster head node for sending the time synchronization signals;

(202) A new startup node establishes a neighbor node list, selects a node with the maximum received signal strength from the nodes with the highest time synchronization level as a time synchronization reference node, and performs master-slave time synchronization;

(203) The new startup node selects an idle ID and initiates a network access request message on a service channel corresponding to the idle ID, wherein the request content comprises the identity information of the node, the time reference node ID and an appointment channel;

(204) After receiving the network access request message, the time reference node of the new startup node forwards the network access request message to a superior time reference node hop by hop and finally sends the network access request message to a network cluster head node;

(205) After receiving the network access request message, the network cluster head node analyzes the network access request message, carries out authentication and authorization on the identity of the new startup node, checks whether the ID applied by the new startup node is occupied or not after passing the authentication and authorization, if not, directly encapsulates the original application ID in the network access successful response message and returns the ID to the new startup node, and if occupied, assigns a reasonable special channel, encapsulates the assigned special channel number in the network access successful response message and returns the ID to the new startup node;

(206) After receiving the response message of successful network access, the new startup node analyzes the ID distributed by the cluster head node of the network, uses the service channel corresponding to the distributed ID as the special channel of the node, and sends a confirmation message of successful network access to the cluster head node on the special channel of the node; meanwhile, the total number of the locally stored network nodes and the ID list information of the network nodes are updated, and the updated time synchronization signal is broadcast and sent on the synchronization channel corresponding to the ID of the node;

(207) After other nodes in the network receive the successful network access confirmation message sent by the newly started node, the total number of the locally stored network nodes and the ID list information of the nodes in the network are updated, and the updated time synchronization signals are broadcast and sent on the synchronization channels corresponding to the respective node IDs.

Wherein, the step (3) comprises the following steps:

(301) Each node in the network updates a common shared channel list based on the total number of nodes in the network, obtains a two-hop neighbor node list of each node by analyzing time synchronization signals of all one-hop neighbor nodes, takes the special channels of all other nodes outside the two-hop range as the special shared channels of each node, and locally maintains the shared channel list including the common shared channels and the special shared channels by each node;

(302) Initiating a shared channel reservation node to check each channel reservation state in a locally maintained shared channel list, selecting an idle shared channel from the channel reservation states, and initiating a reservation request in a special channel of the node;

(303) After a reservation request received by a one-hop neighbor node initiating a shared channel reservation node is received, analyzing a reserved shared channel number, and checking a shared channel list maintained by the node: if the reserved shared channel number does not exist in the table, the processing is not carried out; if the reserved shared channel number exists in the table and is in an occupied state, returning a reservation failure response, and if the reserved shared channel number exists in the table and is in an idle state, returning a reservation success response;

(304) After a TDMA frame, if the starting shared channel reservation node does not receive a reservation failure response from a one-hop neighbor node, a reservation success confirmation message is sent on a corresponding dedicated channel, a local shared channel list is updated, meanwhile, the occupied shared channel which is reserved successfully is started to carry out service data transmission, and the one-hop neighbor node updates the local shared channel list after receiving the reservation success confirmation message; if the reservation initiating node of the shared channel receives a reservation failure response sent by the one-hop neighbor node, updating a local shared channel list and continuing to initiate reservation requests to other idle shared channels;

(305) After the successful reservation shared channel node finishes data transmission, a reservation cancellation message is sent on a corresponding dedicated channel, and a local shared channel list is updated at the same time; and after the one-hop neighbor node receives the reservation cancellation message, updating the local shared channel list.

Compared with the background technology, the invention has the following main advantages:

aiming at a wireless ad hoc network, the invention designs a mixed channel distribution method suitable for the wireless ad hoc network, firstly, a network cluster head node distributes a special channel for a new network access node in a centralized manner, and the reliable transmission of time-sensitive services of each node can be ensured; meanwhile, considering that the special channel of each node has the characteristic of being spatially multiplexed by nodes other than two hops of the special channel, a mechanism for locally maintaining a shared channel list is designed, and a mechanism for reserving and competing on the special channel to occupy the shared channel is provided, so that collision caused by reservation message collision can be avoided, the information interaction times of competing the shared channel can be reduced, and the high-capacity data transmission requirement of each node is finally met. The hybrid channel allocation method fully utilizes all channel resources of the network, is simple and easy to implement, and can effectively improve the transmission capability of the whole network.

Drawings

Fig. 1 shows a new startup node networking/access process according to an embodiment of the present invention.

Fig. 2 shows a reservation procedure of a shared channel at a network node according to an embodiment of the present invention.

Fig. 3 is a frame structure diagram of a wireless ad hoc network.

Fig. 4 is a schematic diagram of a wireless ad hoc network frame synchronization channel slot structure.

Fig. 5 is a schematic diagram of a wireless ad hoc network topology.

Fig. 6 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (network access request).

Fig. 7 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (network access response).

Fig. 8 is a schematic diagram of a wireless ad hoc network frame traffic channel timeslot structure (network access acknowledgement).

Fig. 9 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (reservation request).

Fig. 10 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (reservation response).

Fig. 11 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (reservation confirmation).

Fig. 12 is a schematic diagram of a wireless ad hoc network frame sharing channel slot structure.

Fig. 13 is a schematic diagram of a wireless ad hoc network frame traffic channel slot structure (reservation cancellation).

Detailed Description

The present invention will now be described in more detail with reference to the accompanying drawings, in which embodiments of the invention are shown by way of illustration, and not by way of limitation.

Fig. 3 is a schematic diagram of a frame structure of a wireless ad hoc network based on a TDMA mechanism, wherein each super frame is 2560ms long and is composed of 32 TDMA frames; each TDMA frame is 80ms long and consists of 80 time slots, each time slot is 1ms long, wherein: the first 2 time slots of each TDMA frame are used as synchronization channels, and comprise broadcast time mark sub-frames (SYN _ BC) and synchronization response sub-frames (SYN _ ACK), and are mainly used for time synchronization and information transmission at network nodes; the remaining 78 time slots are traffic channels; the network capacity is at most 64 nodes.

The new boot node networking/accessing process is shown in fig. 1.

1. Network cluster head node network establishment process

Step 1, setting a time synchronization level as the highest level 0 and a node ID as 1 by a network cluster head node, and taking a 1 st service channel TS1 as a dedicated channel of the node; meanwhile, the self clock is directly used as the time stamp information, and the time synchronization signal is broadcast and transmitted on the 1 st synchronization channel of the 1 st TDMA frame, as shown in fig. 4: fill ID =1 in "own node ID"; fill in the "level" the time synchronization level 0 level; filling all 0 in the time reference node ID, which indicates that the node is the highest node of the time synchronization level of the whole network; filling current clock information of the node in the timestamp; filling 1 in the total number of the network nodes; filling the ID of the node in the network node ID list; filling ID =1 in "cluster head node ID"; SYN _ ACK is used for time synchronization under a master-slave synchronization mechanism.

2. Flow for distributing special channel to new network-accessing node by network cluster head node

Taking fig. 5 as an example, the X node is a network cluster head node, the H node is a new start node, and a neighbor node in a hop range thereof is a node B, C, G, I.

Step 2, the node H analyzes time synchronization signals sent by all one-hop neighbor nodes, obtains the ID and the time synchronization level of each one-hop neighbor node, and obtains the information such as the total number of the network nodes, the ID list of the network nodes, the ID of the cluster head node and the like;

step 3, the node H establishes a one-hop neighbor node list { B, C, G, I }, selects a node B with the maximum received signal strength as a time synchronization reference node from a node set { B, C } with the highest time synchronization level, and carries out master-slave time synchronization;

step 4, the node H selects an idle ID =10, and initiates a network access request message on the traffic channel TS10 corresponding to the ID =10, where the network access request is as shown in fig. 6: the network request class message is filled in the "type", the identity information of the node H is filled in the "new node identity information" for authentication, the TS10 is filled in the "reserved channel", and the ID =5 is filled in the "upper reference node ID".

And 5, after receiving the network access request message, the time synchronization reference node B of the node H analyzes the content information of the network access request, carries the information in a special channel of the node B and sends the information to the time reference node A of the node B, and finally sends the information to the network cluster head node X through hop-by-hop forwarding.

Step 6, after receiving the network access request message of the node H, the network cluster head node X analyzes information carried by the network access request, authenticates and authenticates the identity of the node H, and after the authentication and authentication are passed, confirms whether the TS10 applied by the node H is occupied or not by checking the network node ID, if not, directly encapsulates the ID =10 in the network access successful response message and returns the response message to the node H, and if the TS10 is occupied, firstly assigns a reasonable ID, and encapsulates the assigned ID in the network access successful response message and returns the response message to the node H. The network entry response is shown in fig. 7: the "type" is filled with the net response type message, the "original application ID information" is filled with the ID =10 of the node H, the "distribution channel" is filled with the TS10, and the "lower reference node ID" is filled with the ID =2 of the node a.

Step 7, after receiving the response message of successful network access, the node H analyzes that the ID =10 allocated to the node by the cluster head node of the network is obtained, takes the allocated channel TS10 as the dedicated channel of the node, and sends a confirmation message of successful network access to the cluster head node X on the dedicated channel TS 10; the network entry confirmation is shown in fig. 8: the "type" is filled with a network acknowledgement type message, the "reservation channel" is filled with TS10 occupied by node H, and the "upper reference node ID" is filled with ID =5 of node B.

Meanwhile, the node H updates the information such as the total number of the locally stored network nodes and the ID list of the network nodes, locally calculates to obtain a synchronous channel corresponding to ID =10 to obtain a second synchronous channel which is a 5 th TDMA frame, and broadcasts and sends an updated time synchronization signal on the synchronous channel; as shown in fig. 4: fill ID =10 in "own node ID"; fill the time synchronization level 3 level in "level"; fill in ID =5 in "time reference node ID"; filling current clock information of the node in the timestamp; fill 10 in "total number of network nodes"; filling the full network node ID in the network node ID list, and marking one-hop neighbor nodes; filling ID =1 in "cluster head node ID"; SYN _ ACK is used for time synchronization under a master-slave synchronization mechanism.

And step 8, after other nodes in the network receive the successful network access confirmation message sent by the node H, updating the information such as the total number of the locally stored network nodes, the ID list of the nodes in the network and the like, and broadcasting and sending the updated time synchronization signal on the synchronization channel corresponding to the respective node ID.

3. The contention sharing channel reservation procedure is performed at the mesh node, as shown in fig. 2.

Step 9, each node in the network updates a common shared channel list based on the total number of nodes in the network, obtains a two-hop neighbor node list of each node by analyzing time synchronization signals of all one-hop neighbor nodes, takes the dedicated channels of all other nodes outside the two-hop range as the dedicated shared channels of each node, and locally maintains a shared channel list including the common shared channels and the dedicated shared channels by each node;

examples are: after the node H successfully accesses the network, the total number of the network nodes is 10, and the set of the network nodes is { X, A, B, C, D, E, F, G, H, I }, so that each node has 68 common shared channels, namely the set is { TS11, TS12, … …, TS78}; taking node H as an example, the set of nodes outside the two-hop range is { X, D, E, F }, and the set of dedicated shared channels of node H is { TS1, TS3, TS4, TS7}; similarly, the node set outside the two-hop range of node F is { X, A, B, C, G, H, I }, and the dedicated shared channel set is { TS1, TS2, TS5, TS6, TS8, TS9, TS10}; each node locally maintains a list of shared channels, wherein: the reservation state is 0, which indicates that the current channel is the shared channel of the node and is in an idle state; the reservation state is 1, which indicates that the current channel is the shared channel of the node, but is already occupied.

Channel number (8 bits)	Reservation state (1 bit)	Occupation node ID (6 bits)
			00000001	0/1
00000010
			……
01001110

Step 10, the originating shared channel reservation node checks each channel reservation state in the locally maintained shared channel list, selects an idle shared channel from the channel reservation states, and originates a reservation request in the dedicated channel of the node. The reservation request is shown in fig. 9: the shared channel reservation request class message is filled in the type, and the available shared channel number occupied by reservation is filled in the reserved channel number.

Step 11, after initiating the reservation request received by the one-hop neighbor node of the shared channel reservation node, analyzing the reserved shared channel number, and checking the shared channel list maintained by the node: if the reserved shared channel number does not exist in the table, not processing; if the reserved shared channel number exists in the table but is already in an occupied state, returning a reservation failure response, and if the reserved shared channel number exists in the table and is in an idle state, returning a reservation success response. Reservation responses are shown in fig. 10: filling shared channel reservation response type information in the type, filling a node ID for initiating reservation of the shared channel in the reserved node ID, and filling a shared channel number occupied by reservation in the reserved channel number; when the reservation is successful, 1 is filled in the "flag", and when the reservation is failed, 0 is filled in the "flag".

And step 12, after a TDMA frame, if the node initiating the shared channel reservation does not receive a reservation failure response from one hop of neighbor node, the node sends a reservation success confirmation message on a dedicated channel of the node, and updates a local shared channel list. Reservation confirmation is shown in fig. 11: and filling the shared channel reservation confirmation type information in the type, and filling the shared channel number successfully occupied by the reservation in the reserved channel number.

Meanwhile, initiating a shared channel reservation node to start occupying a shared channel which is reserved successfully for service data transmission; and after receiving the reservation success confirmation message, the one-hop neighbor node updates the local shared channel list. As shown in fig. 12.

If the reservation-initiating node of the shared channel receives the reservation-failure response sent by the neighbor node of one hop of the shared channel, the local shared channel list is updated, and the reservation request can be continuously initiated to other idle shared channels.

Step 13, after the successful reservation shared channel node finishes data transmission, it needs to send reservation cancellation message on its dedicated channel, and updates the local shared channel list; reservation cancellation is shown in fig. 13: the shared channel reservation cancellation class message is filled in the type, and the shared channel number for canceling occupation is filled in the reserved channel number canceling. And after receiving the reservation canceling message, the one-hop neighbor node updates the local shared channel list.

Claims (3)

1. A hybrid channel allocation method suitable for a wireless ad hoc network is characterized by comprising the following processes:

(1) After each wireless self-organizing node is started, monitoring 1 superframe period, if no time synchronization signal is heard, taking the wireless self-organizing node as a network cluster head node, and starting a network building process; if one or more time synchronization signals are intercepted, executing the step (2);

(2) The new startup node selects a node with the highest time synchronization signal level as a time synchronization reference node, initiates a network access request process, and allocates a dedicated channel for the new startup node by the cluster head node;

(3) In the network operation process, each node in the network independently maintains a shared channel list of the node, wherein the shared channel list comprises all common shared channels of the nodes in the network and a special shared channel of the node, and the special shared channel is the special channel of all other nodes outside the two-hop range of the node; when the service data quantity exceeds the capacity range, the shared channel is used in a competition mode in a reservation mode.

2. The hybrid channel assignment method for wireless ad hoc networks as claimed in claim 1, wherein the step (2) comprises the steps of:

(201) The newly started node analyzes all the sensed time synchronization signals to obtain the node ID, the time synchronization level, the total number of the nodes in the network, the ID list of the nodes in the network and the ID information of the cluster head node for sending the time synchronization signals;

(202) A new startup node establishes a neighbor node list, selects a node with the maximum received signal strength from the nodes with the highest time synchronization level as a time synchronization reference node, and performs master-slave time synchronization;

(203) The new startup node selects an idle ID and initiates a network access request message on a service channel corresponding to the idle ID, wherein the request content comprises the identity information of the node, a time reference node ID and a reservation channel;

(204) After receiving the network access request message, the time reference node of the new startup node forwards the network access request message to a superior time reference node hop by hop and finally sends the network access request message to a network cluster head node;

(205) After receiving the network access request message, the network cluster head node analyzes the network access request message, carries out authentication and authorization on the identity of the new startup node, checks whether the ID applied by the new startup node is occupied or not after passing the authentication and authorization, if not, directly encapsulates the original application ID in the network access successful response message and returns the ID to the new startup node, and if occupied, assigns a reasonable special channel, encapsulates the assigned special channel number in the network access successful response message and returns the ID to the new startup node;

(206) After receiving the response message of successful network access, the new startup node analyzes the ID distributed by the cluster head node of the network, uses the service channel corresponding to the distributed ID as the special channel of the node, and sends a confirmation message of successful network access to the cluster head node on the special channel of the node; meanwhile, the total number of the locally stored network nodes and the ID list information of the network nodes are updated, and the updated time synchronization signal is broadcast and sent on the synchronization channel corresponding to the ID of the node;

(207) After other nodes in the network receive the successful network access confirmation message sent by the newly started node, the total number of the locally stored network nodes and the ID list information of the nodes in the network are updated, and the updated time synchronization signals are broadcast and sent on the synchronization channels corresponding to the respective node IDs.

3. The hybrid channel allocation method applicable to the wireless ad hoc network according to claim 1, wherein the step (3) comprises the following steps:

(301) Each node in the network updates a common shared channel list based on the total number of nodes in the network, obtains a two-hop neighbor node list of each node by analyzing time synchronization signals of all one-hop neighbor nodes, takes the special channels of all other nodes outside the two-hop range as the special shared channels of each node, and locally maintains the shared channel list including the common shared channels and the special shared channels by each node;

(302) Initiating a shared channel reservation node to check the reservation state of each channel in a locally maintained shared channel list, selecting an idle shared channel from the reservation states, and initiating a reservation request in a special channel of the node;

(303) After a reservation request received by a one-hop neighbor node initiating a shared channel reservation node is received, analyzing a reserved shared channel number, and checking a shared channel list maintained by the node: if the reserved shared channel number does not exist in the table, the processing is not carried out; if the reserved shared channel number exists in the table and is in an occupied state, returning a reservation failure response, and if the reserved shared channel number exists in the table and is in an idle state, returning a reservation success response;

(304) After a TDMA frame, if the starting shared channel reservation node does not receive a reservation failure response from a one-hop neighbor node, a reservation success confirmation message is sent on a corresponding dedicated channel, a local shared channel list is updated, meanwhile, the occupied shared channel which is reserved successfully is started to carry out service data transmission, and the one-hop neighbor node updates the local shared channel list after receiving the reservation success confirmation message; if the reservation initiating node of the shared channel receives a reservation failure response sent by the neighbor node of one hop, the local shared channel list is updated, and reservation requests continue to be initiated to other idle shared channels;

(305) After the successful reservation shared channel node finishes data transmission, a reservation cancellation message is sent on a corresponding dedicated channel, and a local shared channel list is updated at the same time; and after the one-hop neighbor node receives the reservation cancellation message, updating the local shared channel list.

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