CN101296506B - Distributed channel configuration method, wireless meshed network system using the same - Google Patents

Abstract

The invention relates to a distributed channel configuration mechanism and system, which are applicable to a wireless mesh network circumstance. The mutual interference in the entire network does not occur is guaranteed by the channel configuration mechanism, so that the configured bandwidth can be fully utilized without any unnecessary consumption caused by the interference. Time division technique can be utilized by the channel configuration mechanism to cut the transmission time of every wireless network interface card and different non-overlapping channels can be specified respectively indifferent time slots. Due to the time division technique, a plurality of wireless network interface cards can be communicated with a single wireless network interface card simultaneously, and the technique is different from other researches that the nodes of a receiving end and a transmitting end need to be provided with a symmetrical number of the wireless network interface cards. Also due to the feature of the technique, the number of the wireless network interface cards can be increased or reduced randomly on a single node according to different needs in the network, which is an effective method for increasing network flow.

Description

The wireless mesh network system of distributed channel configuration method and use the method

Technical field

The present invention relates to a kind of method and apparatus of wireless network channel assignment, and particularly relate to a kind of method and apparatus of distributed channel configuration mechanism of based on wireless mesh network environment.

Background technology

In recent years, in the fast development of WiMAX access technology, comprising Wi-Fi (IEEE 802.11 series), WiMAX (IEEE 802.16 series) and 3G etc. are arranged.And based on wireless mesh network (Wireless MeshNetwork, beneath abbreviation WMN, IEEE 802.11s) expection will be integrated into one of important technology of wireless broadband network.And the structure of based on wireless mesh network (WMN) just as shown in Figure 1, is a mesh network take interface of wireless transmission as network backbone, and its operating mode is to arbitrarily network (Ad-hoc Network) is very similar.Because this network configuration uses interface of wireless transmission as network backbone, therefore have cloth to build fast and be not subjected to the advantage such as geographical terrain restriction, this kind network often can be applied in the required network of the building of community network, exhibition hall and stand required casual network, disaster area or special geological surrounding etc.

But because WMN forms network backbone with interface of wireless transmission, take IEEE 802.11a/g as example, the transmission bandwidth of its bulletin is 54Mbps (Mega Bytes Per Second, megabytes per second), and this is the transmission bandwidth of maximum possible, but Chang Yinwei is subject to medium access control (Media AccessControl, be called for short MAC) competition (MAC Contention), 802.11 gauge outfit file (Headers), 802.11ACK the impact of signal and bag wrong (Packet Errors) etc. so that average available bandwidth often half less than.

Yet, the most serious problem is that the data transmission rate of network linking layer (Link Layer) is understood the decrease because of the interference of signal, Fig. 2 is two kinds of possible interference phenomenons of explanation: the interference problem of (1) same transmission path, the interference problem of (2) adjacent transmission path.In Fig. 2, the signal covering scope of node (node) 3 comprises node 2,4 and 9, and is identical, and node 3 is also simultaneously in node 2,4 and 9 signal covering scope.When the first transmission path (Path) and the second transmission path are respectively transfer of data the path of process.Take the first transmission path as example, when node 2 with node 3 during at the transmission of data, this moment, node 4 can be received the signal of node 3, thereby cause node 4 temporarily can't follow node 5 the transmission of datas, at this moment, the transmission bandwidth of the first transmission path just is affected, and this phenomenon just is called the interference problem of same transmission path.

Moreover, see again the node 9 on the second transmission path, because it is in the signal covering scope of node 3, so when node 2 with node 3 during at the transmission of data, this moment, node 9 can be received the signal of node 3, thereby causing node 9 temporarily can't follow node 8 or 10 the transmission of datas, the transfer of data of this first transmission path but affects the phenomenon of another transmission path (the second transmission path), just is referred to as the interference problem of adjacent transmission path.Therefore how have successively many researchs to be devoted to inquire into improves its structural design and to promote available transmission bandwidth at WMN.

In IEEE 802.11s WiFi Mesh standard, allow a plurality of interface of wireless transmission to use simultaneously different not overlapping channels (Non-overlapping channel) to transmit, to increase transmission bandwidth.Therefore, there is part research inquiring into many sockets of use card (Multi-Network Interface Card, under be called Multi-NIC) increase the flow of network, its method is roughly at each node a plurality of socket cards is installed, and each socket card can use different not overlapping channels (Non-overlapping channel) and other node communication separately.The advantage of this method is to revise any hardware support body, only need to have complete channel (Channel) distribution mechanism of a cover to be cooperated, and just can reach the purpose of Integral lifting network traffics.

In U.S. 2006/0072502A1 patent disclosure case content, propose a kind of in WLAN the method and system (Method And System For Assigning Channels InA Wireless LAN) of channel distribution.The network environment that this patent motion sets is the Infrastructure pattern (Mode) of WLAN (WLAN), and namely client is to the communication pattern of hub.Mobile node in the network (Mobile Node, under be called MN) be that mode with a jump (One hop) connects access point (Access Point, under be called AP), and the other end of AP is cable network (Wirednetwork), each AP has at least 2 channel to use, and adjacent with another AP at least.

Main is constantly to collect transport load information (Traffic LoadInformation) by each AP, and predict output (Throughput) possible on each channel, then determine that by AP the channel an of the best and the mobile node (MN) in the own signal covering scope lead to.Yet the method for this channel distribution is only considered the optimum channel of a jump (One hop) between AP and MN, to some extent restriction in the application.

In the middle of the more early stage research, there is most inquiring into how to revise the network MAC layer agreement, supporting a plurality of channels (Multiple Channel) Internet Transmission, its main purpose is to find best channel to use during for each single bag transmission, occurs with situation about avoiding interference.And 2 pieces of concepts about many sockets card (Multi-NetworkInterface Card, Multi-NIC) that proposed by people such as the people such as V.Bah1 and P.H.Hsiao, wherein one piece is V.Bahl, A.Adya, J.Padhye, A.Wolman; " Reconsidering the Wireless LAN Platform with MultipleRadios; " Workshop on Future Directions in Network Architecture (FDNA-03), other one piece is P.H.Hsiao, A.Hwang, H.T.Kung, and D.Vlah; " Load-Balancing Routing for Wireless Access Networks, " Proc.of IEEEInfocom 2001 is being taken seriously recently and is beginning a large amount of discussion.The method of this exposure is at the node of each random network (Ad-hoc Network) a plurality of socket cards to be installed, and each socket card can determine to use that channel and other node communication separately dynamically.The advantage of this method is to revise any hardware support body, only need to have once complete channel assignment (Channel Allocation) mechanism of cover to be cooperated the purpose that can reach the enhancement network traffics.Therefore, then there is the people such as A.Raniwala to propose the channel assignment mechanism [A.Raniwala of centralize structure, K.Gopalan, T.Chiueh, " Centralized channel assignment and routing algorithms formulti-channel wireless mesh networks; " ACM Mobile Computing andCommunications Review 8 (2) (2003)], this piece of writing is the paper that early formally defines channel assignment (Channel Allocation) problem, the author utilize oneself the definition evaluating matrix (EvaluationMetric) fulfil load consciousness channel allocation (Load-Aware Channel Assignment) mechanism, whole network is carried out overall calculating, obtain better channel assignment, make overall network traffic maximum.

In recent research, there is again the author in succession to propose dynamically and dispersion (Dynamic ﹠amp; Distributed) the channel assignment correlation technique of structure.Wherein among IEEE 802.11s standard, adopt Common ChannelFramework to exchange channel assignment (Channel Allocation) information.The method of these researchs is based on IEEE 802.11 wlan standards, a plurality of wireless network interface cards is installed to support the network environment of multichannel transmission.But in the above-mentioned technology, still can't avoid situation about interfering with each other.

Summary of the invention

The present invention proposes a kind of channel assignment for multiple wireless network interface mesh network environment (ChannelAllocation) mechanism, can reach the purpose of avoiding internodal interference and reaching Bandwidth guaranteed.

The present invention proposes a kind of Wi-Fi mesh network topology, for be the channel assignment between backhaul router among the WMN (Channel Allocation) mechanism, and based on wireless mesh network (WMN) has a plurality of jumps (Multi-hop) characteristic that is similar to random network (Ad-hoc Network), so the channel assignment of considering not is that the optimum channel of only considering a jump (One hop) between access point (AP) and mobile node (MN) gets final product, but must consider whole piece routed path (Routing Path) all jumps (hop) of process can both be configured suitable channel, and can not disturb original channel that has disposed.

The present invention proposes a kind of distributed channel configuration mechanism for wireless network interface mesh network environment.The mechanism of this channel allocation is guaranteed the situation that can not interfere with each other in whole network, can fill with the bandwidth that reaches configuration and part utilize and can not cause unnecessary consumption because of interference problem.

The present invention proposes a kind of distributed channel configuration mechanism for wireless network interface mesh network environment.The mechanism of this channel allocation is utilized time-division (Time Division) technology, cut the transmission time of each wireless network interface card, in different time slot (Time slot), can specify individually different not overlapping channels (Non-overlapping channel).Also because this technology makes the single wireless network interface card can be simultaneously and a plurality of wireless network interface cartoon letters, being different from other research must have symmetrical wireless network interface card number in receiving end and sending end node.These characteristics can increase and decrease arbitrarily for demands different in the network number of wireless network interface card on single node, be the method for efficient increase network traffics.

The distributed channel configuration mechanism that the present invention proposes is applicable to based on wireless mesh network, and in the method for this distributed channel configuration, the channel use state according to network node determines the free channel between the adjacent node.And according to routed path, from node, select the node of routed path process, and from these nodes, determine start node and destination node.And the free channel that uses according to the selective sequential from the destination node to the start node, to set up routed path.Wherein the selector of free channel is unified shortest path by path (Shortest Routing Path) requirement, and does not reuse identical channel with adjacent node.Wherein, free channel is defined as channel not in order to one of transmission, reception or the arbitrary state that disturbs, and the selection of free channel is not to reuse identical channel according within 3 jumps.

The distributed channel configuration mechanism that the present invention proposes, be applicable to based on wireless mesh network, in the method for this distributed channel configuration, channel according to node uses state, determine the free channel between the adjacent node, and according to routed path, from node, select the node of routed path process, and from node, determine start node and destination node.According to bandwidth requirement, select to increase the socket card quantity of node.The free channel that then uses according to the selective sequential from the destination node to the start node setting up routed path, and meets bandwidth requirement.Wherein the selector of free channel is unified shortest path by path (ShortestRouting Path) requirement, and does not reuse identical channel with adjacent node.Wherein, free channel is defined as channel not in order to one of transmission, reception or the arbitrary state that disturbs, and the selection of free channel is not to reuse identical channel according within 3 jumps; According to bandwidth requirement, select the step of the socket card quantity of increase node to comprise according to routed path and bandwidth, carry out the configuration of channel, wherein, if dispose unsuccessful, then judge whether to exist on the routed path to meet node and use state to surpass one of these nodes of a threshold value greater than integral body use state, if exist, then node is increased a socket card; Wherein,

Node use state is:

Wherein, x ∈ V;

Whole use state is:

Wherein, x ∈ V, wherein,

V is the set of all nodes in the network, and | V| is n, and T is a time slot number, is assumed to be k, T＞0; I _xThe socket card quantity of representation node x; And U _{X, t}The channel number that representation node x has been configured in t time zone, and U _{X, t}≤ I _xAnd 0＜t≤T.

The distributed channel configuration mechanism that the present invention proposes, be applicable to based on wireless mesh network, in the method for this distributed channel configuration, according to a system requirement definition one flowmeter, flowmeter according to routed path and bandwidth requirement, is selected the node of routed path process in order to set these nodes to preset flow and the direction of reception and the transmission of adjacent node from node, and determine start node and destination node, and node is to flow and the direction of adjacent node.According to flow and direction, select the socket card quantity of node.And the free channel that uses according to the selective sequential from the destination node to the start node, setting up routed path, and meet bandwidth requirement, and adjacent node is not reused identical channel.Wherein, free channel is defined as channel not in order to one of transmission, reception or the arbitrary state that disturbs, and the selection of free channel is not to reuse identical channel according within 3 jumps.Wherein calculate with beneath operational formula for the socket card quantity of the required installation of each node:

Wherein, n is the number of all nodes in the network, and B is the total bandwidth of socket card, and T is these socket card number of time slots.

The present invention proposes a kind of device that is applicable to distributed channel configuration in the based on wireless mesh network.This based on wireless mesh network comprises a plurality of nodes, and said apparatus comprises: the channel according to these nodes uses state, determines the module of one or more free channel between the adjacent node; And select the module of the node of process according to a routed path; And from the module of the free channel of the node choice for use on this routed path, to set up this routed path.The selector of these free channels is unified shortest path by path (ShortestRouting Path) requirement, and does not reuse identical channel with adjacent node.Wherein, free channel is defined as channel not in order to one of transmission, reception or the arbitrary state that disturbs, and the selection of free channel is not to reuse identical channel according within 3 jumps.

The present invention proposes a kind of device that is applicable to distributed channel configuration in the based on wireless mesh network.This based on wireless mesh network comprises a plurality of nodes, and said apparatus comprises: according to routed path, select the module of the node of process; Channel according to these nodes uses state, determines the module of one or more free channel between the adjacent node; Select the module of the socket card quantity of increase node according to bandwidth requirement; And the free channel of choice for use to be to set up the module of routed path, and wherein the selector of this free channel unification shortest path is by path (Shortest Routing Path) requirement, and do not reuse identical channel with adjacent node.Wherein, free channel is defined as channel not in order to one of transmission, reception or the arbitrary state that disturbs, and the selection of free channel is not to reuse identical channel according within 3 jumps.Wherein, according to bandwidth requirement, select the module of the socket card quantity of these nodes of increase to comprise according to routed path and bandwidth, carry out the configuration of channel, wherein, if dispose unsuccessfully, then judge whether to exist on the routed path to meet a node and use state to surpass one of these nodes of a threshold value greater than integral body use state, if exist, then this node is increased a socket card; Wherein,

Node use state is: Wherein, x ∈ V;

Whole use state is:

Wherein, x ∈ V, wherein,

V is the set of all nodes in the network, and | V| is n, and T is a time slot number, is assumed to be k, T＞0; I _xThe socket card quantity of representation node x; And U _{X, t}The channel number that representation node x has been configured in t time zone, and U _{X, t}≤ I _xAnd 0＜t≤T.

For above-mentioned feature and advantage of the present invention can be become apparent, preferred embodiment cited below particularly, and cooperation accompanying drawing are described in detail below.

Description of drawings

Fig. 1 is the structural representation of existing a kind of based on wireless mesh network (WMN).

Fig. 2 is that explanation existing network linking layer is because the interference problem of same transmission path or the interference problem schematic diagram of adjacent transmission path.

Fig. 3 illustrates some definition of mentioning in embodiments of the present invention.

Fig. 4 is the channel assignment schematic diagram of mechanism of not use time-division (Time Division) technology of the explanation embodiment of the invention.

Fig. 5 is the defined free channel schematic diagram of channel assignment mechanism of the explanation embodiment of the invention.

Fig. 6 is the channel assignment mechanism of the explanation embodiment of the invention, is used for representing the combination schematic diagram of relevant free channel with one 3 tuples (a 3 for a1, a2).

Fig. 7 is that explanation is according to the mechanism of the channel assignment among Fig. 6, the result that the routed path of setting up (Routing Path) is selected.

Fig. 8 is the channel assignment mechanism of the explanation embodiment of the invention, but the transmission path that shared in common has been configured.

Fig. 9 is after explanation is calculated according to Fig. 8, the embodiment of the free channel group that can obtain.

Figure 10 is the channel assignment schematic diagram of mechanism of (Time Division) technology that adds the time-division in the explanation embodiment of the invention.

Figure 11-the 12nd illustrates and utilizes channel assignment mechanism of the present invention, and 5 routed paths that originally add are one by one added the probable discharge schematic diagram that the General Logistics Department sets each node for.

Figure 13 is that explanation the present invention increases the socket card, to adjust the method flow schematic diagram of overall network traffic.

Figure 14-the 16th, illustrate add the socket card according to Figure 13 after, 5 routed paths that add one by one add the probable discharge schematic diagram that the General Logistics Department sets each node for.

Figure 17 is the channel assignment schematic diagram of mechanism that the explanation embodiment of the invention adopts the static analysis algorithm.

Figure 18-the 21st illustrates that the embodiment of the invention adopts the static analysis algorithm, according to the schematic diagram of step order completing channel configuration.

Embodiment

The definition of related terms

R: the maximum distance that the signal transmission of nodes can reach

D (u, v): the distance of node u and node v

C: represent the set that all non-overlapping channels of this network become

G=(V, E): aeoplotropism graph G=(V, E) represents a Wi-Fi netted (Mesh)

V: the set that is all nodes in the network

E: the set that becomes for all-links in the network (link)

The namely set that becomes of all nodes in the range of signal of node u

S (u, k): the current state of the channel k of node u, kind comprises (Transmitting in the transmission, with " T " expression), receive in (Receiving, with " R " expression), be disturbed (Interfered, with " I " expression) and free (Free is with " F " expression)

S (u, k)=T in the transmission: expression node u is using channel k to send bag, u ∈ V, k ∈ C

S (u, k)=R in the reception: expression node u is using channel k to receive bag

Be disturbed S (u, k)=I:

S (x, k)=T

Free S (u, k)=F:S (u, k) ≠ T and S (u, k) ≠ R and S (u, k) ≠ I

FC _{(u, v)}: this free channel that chains (Free Channel) at (u, v)

$\∀k\∈C,k\∈{\mathrm{FC}}_{(u,v)}\⇔S(u,k)=F/\mathrm{IandS}(v,k)=\mathrm{Fand}\∀x\∈N_u,S(x,k)\≠R$

If with three bit representation free channel groups, then be defined as follows

Suppose that a known routed path can pass through n hop, then by start node to destination node sequentially with P ₁, P ₂... P _nRepresent each hop, P ₁, P ₂... P _n∈ E

${\mathrm{FCS}}_{P_x}\&equiv;\left\{({\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2,c_3)\right|{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\&Element;{\mathrm{FC}}_{P_{x-2}},{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&Element;{\mathrm{FC}}_{P_{x-1}},{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{FC}}_{P_x}\mathrm{and}{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\&NotEqual;{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&NotEqual;c_3\},$ 3≤x≤n

${\mathrm{<figure-callout\; id="2"\; label="FCS\; P"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">FCS</figure-callout>}}_{P_{}}\&equiv;\left\{(-1,{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2,c_3)\right|{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&Element;{\mathrm{<figure-callout\; id="1"\; label="FC\; P"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">FC</figure-callout>}}_{P_{}},{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{<figure-callout\; id="2"\; label="FC\; P"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">FC</figure-callout>}}_{P_{}}\mathrm{and}{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&NotEqual;c_3\}$

${\mathrm{<figure-callout\; id="1"\; label="FCS\; P"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">FCS</figure-callout>}}_{P_{}}\&equiv;\left\{(-2,-1,c_3)\right|{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{FC}}_{P_1}\}$

The summary of the invention explanation

The present invention is based on based on wireless mesh network (the Wireless Mesh Network of IEEE 802.11s WiFi Mesh standard construction, WMN), in conjunction with time-division (Time Division) and space designed channel allocation (Channel Allocation) mechanism of (Spatial Reusable) technology of can resetting, dynamic distributed channel allocation (Dynamic Distributed Channel Allocation for example, the beneath DDCA that is called for short) mechanism, or static channel distribution mechanism.In the based on wireless mesh network of any network topology (Topology), a plurality of mesh network nodes (Node) interconnection, each node can independently be carried out channel allocation mechanism.Channel allocation mechanism is the channel assignment that the mode of adopting distributed (Distributed) calculates each wireless link (Link).Refer to reuse identical channel (Channel) in complete nonoverlapping time zone (Time-slot) in this time-division of adopting, and can reset and refer to can reuse identical channel outside spatially the segment distance in the space.These two mechanism allow a plurality of interface of wireless transmission as arranging in pairs or groups again, use simultaneously different non-overlapping channels (Non-overlapping Channel), just can increase the service efficiency of transmission bandwidth.

The present invention can require dynamic-configuration suitable non-overlapping channel and reserved bandwidth by path (Shortest Routing Path) according to different shortest paths, the action of calculating can by routed path (Routing Path) the network node complete independently of process, and the interference problem of same path and adjacent path can not occur in the channel that can avoid disposing, takes full advantage of effective bandwidth.Just because of the present invention can avoid interference problem, can not cause too much bandwidth consume because of interference problem, be used in the applied environment of needs QoS so extremely be fit to cover.

The present invention proposes a cover distributed channel distribution mechanism under take IEEE 802.11s WiFi Mesh standard as the WMN on basis, but this mechanism is in conjunction with time-division and space reset technique, each socket is divided into a plurality of transmission time zone, same channel can be reconfigured in same time zone beyond suitable distance, the single network interface can be transmitted with a plurality of sockets simultaneously, and allow the socket number of receiving end and sending end node that asymmetric characteristic is arranged, allow the installation of socket have more elasticity.

Under above many mechanism combination, can reduce for the localized network node demand number of socket card, the utilization rate of easier raising web channel and bandwidth.Yet in order to reach the effect of time-division, whole netted (Mesh) network node is essential can synchronization slot.Therefore, in a shared network interface card of each node installation (Common-NIC), all shared network interface card are all used identical channel and adjacent node exchange, comprise the information such as the configuration of channel and synchronizing information, guaranteeing correctly configure channel of each network node, and clearly know when begin and when finish to transmit.

The transmission path that utilizes this mechanism to set up can be avoided the interference of same transmission path and the interference of adjacent path simultaneously, to reach needed bandwidth requirement.Therefore invention characteristics of the present invention comprise: (1) shared network interface card of each node installation in network, the shared network interface card of all nodes is all used same channel and adjacent node exchange message.The information of exchange comprises that node itself is at present in the channel that uses, the channel that is about to configuration and time synchronized etc.(2) design dynamic distributed channel allocation (DDCA) mechanism.This mechanism is under the hypotheses that routed path has determined, intercourse information by the node on this routed path, just can determine dynamically this routed path the channel that should use between the node of process, the interference problem of same transmission path and adjacent path can not occur to guarantee the whole piece routed path.When selecting channel, consider the characteristic of as far as possible utilizing co-route (Common Path), preferentially select the channel that has disposed and enough remaining bandwidths are arranged, so can significantly reduce the consumption of available channel in the network.(3) utilize time division technique to cut transmission period of network interface card (NIC) on each node, with the more efficient remaining bandwidth that uses each node.Because time division technique can allow node adjacent one another are know mutually when this begins and finish data transmission, and can allow NIC transmit from the NIC of different nodes simultaneously, therefore can be because the NIC on a certain node only disposes wasting problem to the very little routed path of a certain bandwidth requirement.In addition, because can allow a NIC transmit with a plurality of NIC simultaneously, so the asymmetric advantage of adjacent node NIC number is arranged, this advantage is suitably to dispose the NIC number for the different bandwidth demand of each node in the network, reaches best cost and benefit ratio.(4) provide a kind of static analysis algorithm, building needed for network is to precompute the optimal NIC number of each node according to the probable discharge of each node, to improve the efficient of web channel configuration.

The present invention proposes a kind of channel assignment mechanism for multiple wireless network interface mesh network environment, based on the multiple wireless network interface card (Multi-NIC) of IEEE 802.11a/b/g wlan standard with based on the dynamic distributed channel allocation mechanism under based on wireless mesh network (WMN) environment of IEEE802.11s WiFi Mesh standard, its characteristics comprise that at least (1) dynamically determines employed channel between node; (2) finish (namely distributed frame) by each node disjoint calculating; (3) guarantee can not occur in the network problem that same transmission path and adjacent transmission path disturb; (4) at each node a shared network interface card (Common-NIC) and adjacent node exchange message are installed; (5) adopt time division technique, the single wireless network interface card can be communicated by letter with a plurality of wireless network interface simultaneously, and have the asymmetric characteristic of wireless network interface card number of receiving end and sending end node; And (6) employing static analysis algorithm, building needed for network is according to the probable discharge of each node, to precompute the optimal NIC number of each node.

To illustrate progressively that below the present invention reaches the concrete technological means of purpose.Before this, please first with reference to shown in Figure 3, mainly be that some definition of mentioning in embodiments of the present invention are described.In Fig. 3, the signal transmission that R represents nodes can reach distance farthest.The distance of D (a, b) representation node a and node b.N _iThe set that all nodes in the range of signal of={ } representation node i become, for example N in the icon _a=node in the b, the range of signal of e} representation node a comprises node b and node e, and N _b={ a, the node in the c, the range of signal of d} representation node b comprises node a, c and d.And there is the state of link (Link) in (a, b) representation node a to node b.

At first, utilize the example of Fig. 4 to explain definition, in this example, do not use the time-division (TimeDivision) technology.Suppose to know that a shortest path is n1 by the source Nodes of path (Shortest Routing Path), and destination node is n5, the node of meeting process is n2, n3 and n4 etc. in the way.And suppose that operable non-overlapping channel (Non-overlapping Channel) has 4, is divided into the first channel to the four channels.And each node in the network can record the own present state of each channel, state is divided into into 4 kinds, be respectively (Transmitting in the transmission, with " T " expression), receive in (Receiving, with " R " expression), be disturbed (Interfered, with " I " expression) and free (Free is with " F " expression).

Suppose that the first channel as a node n1 is that (T) state is when (representing with left oblique line in the diagram) in the transmission, representation node n1 is using the first channel to send bag (Packet).Identical, for receiving (R) state (representing with right oblique line in the diagram), expression node n3 is using the 3rd channel to receive bag such as the 3rd channel of node n3.And when the 3rd channel of node n1 for being disturbed (I) state (representing with the intersection lines in the diagram), then being illustrated in is just having certain node to use the 3rd channel sending bag in the range of signal of node n1, and node n1 itself receives (Receiving) node.Other situation then is free (F) state (representing with blank in the diagram).

Then define free channel, so-called node n1 to the first channel of node n2 be free state, the first channel that node n1 is said in expression is to be disturbed or free state (Interfered/free state) and the first channel of node n2 is free state, and the first channel of all nodes is to transmit/be disturbed/free state in the range of signal of node n1.If therefore when node n1 has the first free channel to node n2, represent that then node n1 can use the first channel to send bag to node n2 (then not all right) in the other direction, and guarantee can not bump with other node.The state of adjacent node then is to exchange each other through common network interface card (Common-NIC) to obtain.

Therefore, take Fig. 5 as example, when hypothesis does not have other network node to exist, then each node through can obtain after calculating node n1 to the free channel between the node n2 be the second channel and the 4th channel (below with { 2,4} represents), and the free channel of n2 to n3 is the first channel, the second channel and the 4th channel.

By that analogy.If be to guarantee to be configured also can interfere with scarcely any channel that in network, has been configured via the drawn free channel of above-mentioned action, so this point guarantees can not occur the interference problem of adjacent transmission path.

The first specific embodiment-basic channel configuration mechanism

At first, first with single time zone (Timeslot), four channels and four socket card structure example explanation channel assignment (Channel Allocation) mechanism.Owing to only have single time zone, so individual other socket card (NIC) all can only be simultaneously and another socket cartoon letters, so in this example, suppose that first the socket card number of each node is identical with non-overlapping channel number.

At first define the combination that 3 tuples (a1, a2, a3) are used for representing relevant free channel, a3 is the free channel of current link, and a2 is the free channel of the link in front, and a1 and representative are the free channels of two links in front.The result of continuity Fig. 5 is through calculating the result that will obtain such as Fig. 6, the FC in the diagram _{(u, v)}The free channel of representative from node u to node v, and

Then represent thus among the embodiment with the selected path of 3 tuples.

Beneath is the free channel combination

Definition:

${\mathrm{FCS}}_{P_n}\&equiv;\left\{({\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1,{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2,c_3)\right|{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\&Element;{\mathrm{FC}}_{P_{n-2}},{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&Element;{\mathrm{FC}}_{P_{n-1}},{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{FC}}_{P_n}\mathrm{and}{\mathrm{<figure-callout\; id="1"\; label="c"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">c</figure-callout>}}_1\&NotEqual;{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&NotEqual;c_3\},$ 3≤n≤4

${\mathrm{<figure-callout\; id="2"\; label="FCS\; P"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">FCS</figure-callout>}}_{P_{}}\&equiv;\left\{(-1,{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2,c_3)\right|{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&Element;{\mathrm{<figure-callout\; id="1"\; label="FC\; P"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">FC</figure-callout>}}_{P_{}},{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{<figure-callout\; id="2"\; label="FC\; P"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">FC</figure-callout>}}_{P_{}}\mathrm{and}{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_2\&NotEqual;c_3\}$

${\mathrm{<figure-callout\; id="1"\; label="FCS\; P"\; filenames="S071A1984220070511E000011.png,S071A1984220070511E000111.png"\; state="\{\{state\}\}">FCS</figure-callout>}}_{P_{}}\&equiv;\left\{(-2,-1,c_3)\right|{\mathrm{<figure-callout\; id="3"\; label="c"\; filenames="S071A1984220070511E000111.png,S071A1984220070511E000121.png"\; state="\{\{state\}\}">c</figure-callout>}}_3\&Element;{\mathrm{FC}}_{P_1}\}$

The method of basic channel configuration mechanism proposed by the invention is if comprise P with Fig. 6 ₁, P ₂, P ₃, P ₄The routed path of four links is example, comprises first from FCS _P4In select at random the combination of one group of relevant free channel, be assumed to be

Then, more sequentially from

In, one group of random choose

Wherein satisfy condition

And

Then sequentially from

Arrive

Namely oppositely select channel from last link in path, until first link.If extremely

Can both select smoothly, then

Be the channel assignment on the whole piece routed path.

In Fig. 6, link P between node n1 and the n2 ₁Just have (2,-1,2) reach (2,-1,4) these 2 groups of free channel groups, because the free channel between node n1 and the n2 is 2 with 4, and this link is the 1st link of routed path (Routing Path), so this field of a1 is with " 2 " expression, this field of a2 then represents with " 1 ".Link P between node n2 and n3 ₂Then have 4 groups, be 2 groups of free channel groups of previous link to be matched with the free channel that links at present form, and only stay all unduplicated combinations (a1, a2 and a3 do not choose the free channel of repetition).

The method of selecting at last channel is last the link P by the path ₄Beginning in the example of Fig. 6, because node n4 to n5 only has a free channel group (4,1,2) to use, therefore can only be selected this combination.When selecting this combination, expression node n4 to n5 can select the second channel (because a3 is 2).And because a1 be 4 and a2 be 1, then so that this link of node n3 to n4 can only be selected free channel group (2,4,1).And node n3 to n4 has selected free channel group (2,4,1) afterwards, and node n2 to n 3 can only select free channel group (1,2,4).And node n2 to n3 has selected free channel group (1,2,4) afterwards, and node n1 to n2 can only select free channel group (2 ,-1,2).With above-mentioned selection mode, label 610,612 as shown in Figure 6,614 and 616 orders then can obtain the result that the routed path (Routing Path) such as Fig. 7 is selected, such as the path arrow of the figure first half and the grey marked position of figure Lower Half.

Because have under the prerequisite of shortest path by path (Shortest Routing Path) requirement, so as long as within 3 jumps (Hop), do not reuse identical channel, can guarantee that then the channel that disposes on this paths will can not bump mutually, thus the channel assignment of present embodiment (ChannelAllocation) mechanism the interference problem of same transmission path can not occur.

The transmission path that the second embodiment-employing priority allocation shared in common has been configured

Then expand the method for above-described embodiment, propose further embodiment, with the transmission path that allows channel assignment mechanism of the present invention can shared in common be configured, can significantly increase the effective utilization of network.If the status modifier of former Fig. 4 is become situation such as Fig. 8, and hypothesis has existed the channel of configuration transmitting bag (Packet), respectively shown in the arrow that label is 810,820 and 830 between node n1 to n2, node n2 to n3 and node n3 to n4.This example in Fig. 8, node n1 to n2 has been configured the first channel, and node n2 to n3 has been configured the 3rd channel, and node n3 to n4 has been configured the 4th channel.When the remaining bandwidth of the channel that has been configured during still greater than at present that newly-built routed path is required bandwidth, the channel that has disposed also can be added in the tabulation of free channel.

Therefore after calculating according to Fig. 8, can obtain an embodiment of free channel group as shown in Figure 9.In this embodiment, according to whether being the channel that has had configuration, and the routed path that needs foundation, with Fig. 9 indicate number 910 be set as five-star 3 grades preferential, and will indicate number 920,921,922,923,924 and 925 be set as second advanced 2 grades preferential, preferential with 1 grade that is set as time one-level with indicating number 930, be set as nonpreemption and will indicate number 940.

So, when node n4 to n5 wants configure channel, if consider priority, will preferentially select (3,4,1) or (3,4,2) wherein a group.Suppose that the link between node n4 to n5 selected (3,4,1) this combination, the link between node n3 to n4 selects (1 so, 2,4) this combination, the link between node n2 to n3 selects (1,1,3) this combination, and (2 ,-1,1) this combination is selected in the link between node n1 to n2.It is the channel assignment shown in 950,952,954 and 956 the arrow that last channel assignment result will indicate number as shown in Figure 9.

The channel assignment mechanism of the 3rd embodiment-zone, multichannel and single socket card structure

Introduce another feature of the present invention among this embodiment, add the time-division (Time Division) technology in the channel assignment mechanism of namely formerly introducing, therefore can be so that the socket card number of receiving terminal and transmission end node be asymmetric.Among this embodiment with cut into 3 time zones (Timeslot), 4 non-overlapping channels, and each node of hypothesis situation that a socket card (NIC) only is installed channel assignment mechanism of the present invention is described.

Please refer to Figure 10, at first again explanation, channel use state comprises (R) in (T) in the transmission, the reception, is disturbed (I) and free (F).And in Figure 11, (T) state illustrates that to represent with left oblique line channel is transmitting bag in the transmission.(R) state of reception represents with right oblique line, illustrates that channel is receiving bag.(I) state that is disturbed represents to intersect lines, illustrate that just having certain node to use this channel to send in the range of signal of node wraps, and this node itself is not receiving node.Other situation then is free (F) state, represents with blank in the diagram.

Owing in the example of Figure 10, added time division technique, so must redefine free channel.If suppose that the first channel in the first time zone of node n1 to n2 is free channel, mean in the first time zone, the socket card number that the sum total number of (T) state and reception (R) state must be installed less than node in the transmission of other channel of node n1 and n2 (except the first channel) (be exactly must less than 1 at present example), and the first channel of node n1 is to be disturbed (I) state or free (F) state, the first channel of node n2 is free (F) state, and the first channel of all nodes in the range of signal of node n1 is not to receive (R) state.

If use I _jThe channel I that represents time zone j, take Figure 11 as example, the free channel of node n1 to n2 has 1 ₂, 3 ₂, 4 ₂Totally 3 free channels, the free channel of node n2 to n3 has 1 ₁, 2 ₁, 3 ₁, 4 ₁Totally 4 free channels, and node n3 to n4 has 7 free channels, node n4 to n5 has 10 free channels.Then adopt previous basic skills, the channel that then can determine last configuration can same path and the interference problem of adjacent path.

When node n4 to n5 wants configure channel, if select (1 ₁, 1 ₃, 2 ₂) this group, the link between node n3 to n4 selects (1 so ₂, 1 ₁, 1 ₃) this combination, the link between node n2 to n3 selects (1,1 ₂, 1 ₁) this combination, and the link between node n1 to n2 selects (2 ,-1,1 ₂) this combination.It is the channel assignment shown in 1010,1020,1030 and 1040 the arrow that last channel assignment result will indicate number as shown in figure 10.

The channel assignment mechanism of the 4th embodiment-dissymmetric network interface card number

Then with Figure 11 some more complicated situations are described, are applied on the channel assignment of dynamic network.The distribution situation of this topology network such as Figure 11, such distribution are very common WMN backbone structure.Suppose that the transmission time will cut into 3 time zones (Timeslot), and 5 non-overlapping channels are arranged, a socket card only is installed on each node, and is supposed that the maximum bandwidth in each time zone is 54M.Then sequentially set up 5 routed paths (Routing Path), be respectively

(1) A → B → E → F → G → H requires the bandwidth of 10M.

(2) C → D → E → F → G → H requires the bandwidth of 10M.

(3) B → E → F → G → I requires the bandwidth of 15M.

(4) F → E → D → C requires the bandwidth of 30M.

(5) H → G → F → B requires the bandwidth of 15M.

The channel of all nodes all is free (F) state when initial, so after the configuration of complete (1) individual routed path, will obtain result as shown in figure 11.The digital representative of annotation is that how many bandwidth this channel that has disposed has kept to the routed path that is transmitting at present in grid.According to the parameter of mentioning in the diagram, be respectively whole use state (Global Utilization), node use state (Node Utilization) and absolute error value (Absolute Deviation), be defined as follows described.In this hypothesis | V| is assumed to be n, and V is the set of all nodes in the network; And T is time slot (Timeslot) number, is assumed to be k, T＞0; I _xThe NIC quantity of representation node x; And U _{X, t}The channel number that representation node x has been configured in t time zone, U _{X, t}≤ I _xAnd 0＜t≤T.

Node Utilization (NU _x):

X ∈ V wherein.

Global Utilization (GU): X ∈ V wherein

Absolute Deviation：

Whole use state GU is 0.37 as can be known in Figure 11, and the absolute deviation value is 2.39.Take node A as example, its node uses state to be 1/3=0.33, therefore uses state GU to differ 0.04 with integral body, if and take Node B as example, its node uses state to be 2/3=0.67, therefore use state GU to differ 0.3 with integral body, other parts sign as shown, no longer superfluous stating.

Following shown in Figure 12 is the routed path configuration of finishing (1)-(3), just preparing to carry out the configuration of (4) individual routed path this moment, yet find that (4) individual path is with the path reverse transfer of (1)-(3) this moment, so can't jointly use the channel that has before configured, when preparing to require to dispose new channel, but find to only have D → C to still have unnecessary free channel, and F → E and E → D can be with (in the icon with null sets without any free channel

Expression), therefore (4) individual routed path build will be failed.Can find in the example thus, the co-route of network part (E ← → G), though be channel or the bandwidth ratio network end-point that all can consume (C ← → D) to come fast, even still have endways available free channel or bandwidth, but but can use up and idle waste because of free channel or the bandwidth of co-route.

But the channel assignment mechanism of the embodiment of the invention has the socket card asymmetrical characteristic of transmission end and receiving terminal node, therefore as long as for free channel or faster node increase of bandwidth consumption socket card, just can significantly increase the utilization rate of channel and the network bandwidth, promote the flow of overall network.Please refer to Figure 13, is that explanation the present invention increases the socket card to adjust the method flow schematic diagram of overall network traffic.At first, in step 1310, according to known routed path and bandwidth, require to carry out the configuration of channel.Then in step 1320, judge whether configuration successful, if then finish the operation of configuration such as step 1330.If but dispose unsuccessfully, then judge whether to exist on this path to meet NU _x-GU is greater than the node of threshold value (Threshold Value).If there is NU _x-GU then increases a socket card with this node x greater than the node of threshold value.If do not exist, then finish configuration such as step 1330.

In Figure 14, be to increase a socket card for node E, then E → D of node E can use without any free channel at this moment Situation then do not exist, node uses state to be 3/6=0.5.In Figure 15, be to increase a socket card for node D and F.In Figure 16, be to increase a socket card for node D and F.Then (4) can both dispose smoothly with the requirement of (5) individual routed path and to finish at last.

In the above-described embodiments, propose a kind of channel assignment for multiple wireless network interface mesh network environment (Channel Allocation) mechanism, can reach the purpose of avoiding internodal interference and reaching Bandwidth guaranteed.

Dynamic analysing method of the present invention has been introduced in previous description, increase one by one routed path and bandwidth requirement (Bandwidth Requirement) with dynamical fashion, socket card (NIC) number of the required installation of each node in the phase-split network.In dynamic analysis of the present invention, defined respectively node and used state (Node Utilization) and whole use state (Global Utilization).When increasing routed path and bandwidth requirement newly one by one, if during configuration failure, then can check the node on this paths, whether exist node to use the difference of state and whole use state greater than certain critical value, and after these nodes are respectively increased a socket card, re-start again the configuration of this routed path.Via adjusting different threshold values, the channel that will affect overall network uses state (Channel Utilization), and the rate that blocks (Blocking Rate) of configuration, therefore use the progressively effect that when different threshold values (Threshold Value), network caused of emulation of dynamic analysis.

But build for network, needed is to precompute the optimal NIC number of each node according to the probable discharge of each node, yet dynamic analysis mode can not provide such information, therefore, the present invention has further proposed another kind of static analysis algorithm.

The 5th embodiment-static analysis algorithm

We adopt the example of Figure 11 at this, and 5 routed paths that originally add are one by one added the probable discharge that the General Logistics Department sets each node for.Figure 17 is shown is that bandwidth requirement with 5 routed paths adds the General Logistics Department, and each node then can be drawn similar pattern according to service and bandwidth that pre-imagination provides to flow and the direction of adjacent node for the network cloth person of building.Then will the static analysis algorithm be described with this topology network and preset flow.

Suppose the predetermined topology network that builds such as Figure 17 of the person of building of network, and each node is delivered to adjacent node and the flow received by adjacent node and direction just shown in thick line arrow among the figure and blue line arrow.Do not had at this moment the information of routed path, only recorded total flow and direction, these information can represent with a form.

At flowmeter of this definition (Flow Table is called for short FT), as shown in Table 1, preset flow and the direction of each node and adjacent node is described.I is listed as the j hurdle then with FT in the form _IjRepresent it, it is defined as follows:

FT _Ii=0,

Wherein n is the sum of nodes.

If FT _Ij＞0, then representing by node i has preset flow (otherwise also representation node j receives the total flow that is sent by node i) to node j

Therefore the relations such as the default topology network of Figure 17 and direction of the traffic can be represented with table one that for example the node F among Figure 17 has preset flow 45M (sum total of thick-line arrow 30+15) to node E, then the 6th being listed as the 5th hurdle and recording 45 expressions in Table 1.

Table one: network flow scale

Node	A	B	C	D	E	F	G	H	I
										A		10
B					25
										C				10
D			30		10
										E		15		30		35
F					45		35
										G						15		20	15
H							15
										I

The information such as preset flow and direction are being changed as behind the table one, just can utilize following listed formula to calculate the NIC quantity of the required at least installation of each node, to satisfy the flow of presetting.It is designed that certain this formula is based on channel assignment mechanism of the present invention, because mechanism of the present invention can effectively solve interference and have the resource denominator, the NIC number that the so easy required installation of each node of formula accurate Calculation just can be arranged allows the network person of building can be in advance according to wanting that the service that provides does the configuration design of full blast.

For the NIC number of the required installation of any one node i in the network just as formula (1) represented it:

Wherein, n is the number of all nodes in the network, and B is the total bandwidth (Total Bandwidth) of NIC, and T is NIC time slot (Timeslot) number in the network.

Comprise 2 topmost parts in the middle of the formula (1), independently go out respectively following formula (2) and formula (3) illustrates.The meaning of formula (2) representative be by node i to all adjacent nodes, the minimum time zone number that the bandwidth that meets the demands is required.Because must independently use different time zones to transmit toward the flow of different directions, thus in formula will toward one party to the general requirements bandwidth get " upper Gauss " computing after divided by indivedual time zones bandwidth and obtain past wherein one party to required time zone number.Add up at last the required time zone number of all directions and be gained.Otherwise formula (3) is for requiring the required minimum time zone number of bandwidth by all adjacent nodes of node i to these directions of node i.At last, the sum total representative of formula (2) and formula (3) be that node i transmits and receive required time zone number sum total, therefore again this numerical value is got " upper Gauss " after divided by number of time slots and is the NIC number that node i needs at least.

Therefore, the information that table one is recorded can accurately calculate the required NIC number of each node such as the result of table two after calculating via formula (1), and the NIC number that each node is required is described.We suppose that the total bandwidth of each NIC is 150M (B parameter) in the middle of table two, and number of time slots is 3 (parameter T), no matter be the NIC number that adjustment B parameter or parameter T can affect the required dress of each node.

Table two: the NIC demand number of each network node

Node serial number	A	B	C	D	E	F	G	H	I
										The NIC number	1	1	1	2	2	2	2	1	1

Below utilize the example of a static configuration channel to come the result of instruction card two really can satisfy bandwidth requirement.The different of dynamic-configuration maximum of introducing among static configuration and the previous embodiment are, static information is only known the outflow of each node and is flowed into bandwidth and direction, and the information of whole piece routed path is arranged unlike dynamic-configuration, therefore allow the order of static configuration sequentially carry out from large to small according to outflow and the inflow bandwidth of each node, being different from the dynamic-configuration situation is to carry out according to sequentially increasing individually routed path newly.

Table three: static configuration order

What table three was listed is the order that each node carries out static configuration, the bandwidth that flows out with each node respectively sorts from large to small, when if the outflow bandwidth is identical, preferential to flow into bandwidth the greater again, the order that is this node of step order hurdle representative in the form.Fig. 3 to Fig. 6 is respectively the result after each node sequentially disposes.

What Figure 18 showed is the channel behaviour in service of each node after the static configuration of completing steps order 1, can learn that by table three node that will carry out step order 1 is node E, and only consider the outflow bandwidth of each node in when configuration, take this moment as example, node E has the flow toward three different directions: (1) to Node B has 15M, (2) to have 30M, (3) 45M to be arranged to node F to node D.Therefore node E finishes after the flow configuration of different directions, and its result will be represented such as Figure 18.Because initial default each node is all only installed a NIC, and setup parameter B=150 and T=3, wherein B is the total bandwidth of NIC, and T is NIC number of time slots in the network.So the outflow bandwidth of node E is in the smooth configuration successful of the situation of only having a NIC.

Figure 19 then is the result who carries out after step order 2 configuration, and the outflow bandwidth that the node F that carries out step order 2 this moment has 2 directions must dispose, and is respectively (1) to the 45M of node E and (2) to the 35M of node G.Because node E when step order 1 after the configure channel, is not just having other unnecessary channel to use, therefore at this moment flowing out bandwidth by node F to the 45M of node E can't dispose smoothly, must increase a NIC in that node E.Become 2 NIC so must first node E be set when carrying out step order 2, each node channel operating position of carrying out after step order 2 disposes will be represented such as Figure 19.

Figure 20 is result after step order 3 is carried out, what carry out in step order 3 is the outflow band width configuration of node G, identical, because the newly-increased flow configuration of the free channel of node G and node F deficiency, so node G and all necessary configurations that increases a NIC ability completing steps order 3 of node F.

Last Figure 21 is the end product that step order 4 is all finished to step order 9, all finish the flow configuration of outflow when all nodes after, even if all action of configuration are finished.To finish at last the NIC number that all preset flow configurations may need if show from the result of this figure, and required complete and table two the coming to the same thing via calculating of NIC number of each node, explanation is under based on channel assignment algorithm of the present invention, formula (1) can accurately calculate the needed NIC number of each node really, will help the network person of building design and planning network.

In sum, the present invention can determine to carry out channel assignment under the WMN based on the construction of IEEE 802.11s WiFi Mesh standard, and guarantee can not occur the problem that same path or adjacent path are disturbed, because behind the joining day cutting techniques, but allow the transmission of socket card one-to-many and the asymmetric characteristic of sending and receiving end socket card so that the present invention has, allow network cloth build to have more elasticity and can significantly promote the utilization rate of channel and bandwidth.

The present invention proposes a kind of distributed channel configuration (Channel Allocation) mechanism for multiple wireless network interface mesh network environment, can reach the purpose of avoiding internodal interference and reaching Bandwidth guaranteed.

The present invention proposes a kind of Wi-Fi mesh network topology, for be channel assignment (Channel Allocation) mechanism between rearmounted network router among the WMN (Backhaul Router), and based on wireless mesh network (WMN) has a plurality of jumps (Multi-hop) characteristic that is similar to random network (Ad-hoc Network), so the channel assignment of considering not is that the optimum channel of only considering a jump (One hop) between access point (AP) and mobile node (MN) gets final product, but must consider whole piece routed path (Routing Path) all jumps (hop) of process can both be configured suitable channel, and guarantee can not disturb original channel that has disposed.

The present invention proposes a kind of distributed channel configuration (Distributed Channel Allocation) mechanism for multiple wireless network interface mesh network environment.The mechanism of this channel allocation is guaranteed the situation that can not interfere with each other in whole network, can fill part utilization and can not cause unnecessary consumption because of interference problem with the bandwidth that reaches configuration, because for example do not reusing identical channel within 3 jumps (hop), can guarantee that then the channel that disposes on this path can not bump mutually.

The present invention proposes a kind of mechanism that disposes (Channel Allocation) for the distributed channel of multiple wireless network interface mesh network environment.The mechanism of this channel allocation is utilized time division (TimeDivision) technology, cut the transmission time of each wireless network interface card, in the different period (Timeslot), can specify individually different not overlapping channels (Non-overlapping channel).Also because this technology makes the single wireless network interface card can be simultaneously and a plurality of wireless network interface cartoon letters, being different from other research must have symmetrical wireless network interface card number in receiving end and sending end node.These characteristics can increase and decrease arbitrarily for demands different in the network number of wireless network interface card on single node, be the method for efficient increase network traffics.

Although the present invention discloses as above with preferred embodiment; so it is not to limit the present invention; have in the technical field under any and usually know the knowledgeable; without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking the claim person of defining of the present invention.

Claims (16)

1. one kind is applicable to the method that distributed channel disposes in the based on wireless mesh network, and wherein, this based on wireless mesh network comprises a plurality of nodes, and the method comprises:

Channel according to these nodes uses state, determines one or more free channel between these adjacent nodes;

According to a routed path, from these nodes, select the node of this routed path process, and from these nodes, determine a start node and a destination node; And

According to these free channels of the use of the selective sequential from this destination node to this start node, to set up this routed path;

Wherein, the selector of these free channels unification shortest path is by the path requirement, and the node adjacent with these do not reused identical channel;

Wherein, should or these free channels be defined as this or these channel not in order to transmit, to receive or one of arbitrary state that disturbs, the selection of this free channel is not to reuse identical channel according within 3 jumps.

2. if the method for distributed channel as claimed in claim 1 configuration is wherein with 3 tuple a1, a2, a3 represents the combination of this free channel, then this a3 is the free channel of current link, and a2 is the free channel of the link in front, and a1 and representative are the free channels of two links in front.

3. the method for distributed channel as claimed in claim 1 configuration, wherein, if these nodes on this routed path have been configured one or more transmission path, then give this or these transmission path one priority, then pay the utmost attention to the transmission path with this priority in the selection of this free channel.

4. the method for distributed channel as claimed in claim 1 configuration wherein, is used state at the channel according to these nodes, determine to add time division technique in the step of this or these free channel, with increase spendable should or these free channels.

5. one kind is applicable to the method that distributed channel disposes in the based on wireless mesh network, and wherein, this based on wireless mesh network comprises a plurality of nodes, and the method for this distributed channel configuration comprises:

According to a routed path, from these nodes, select these nodes of this routed path process, and from these nodes, determine a start node and a destination node;

Channel according to these nodes uses state, determines one or more free channel between these adjacent nodes;

According to a bandwidth requirement, select to increase the socket card quantity of these nodes; And

These free channels that use according to the selective sequential from this destination node to this start node setting up this routed path, and meet this bandwidth requirement;

Wherein, the selector of these free channels unification shortest path is by the path requirement, and the node adjacent with these do not reused identical channel;

Wherein, should or these free channels be defined as this or these channel not in order to transmit, to receive or one of arbitrary state that disturbs, the selection of this free channel is not to reuse identical channel according within 3 jumps;

Wherein, according to this bandwidth requirement, select the step of the socket card quantity of these nodes of increase to comprise according to this routed path and this bandwidth, carry out the configuration of channel, wherein, if dispose unsuccessfully, then judge whether to exist on this routed path to meet a node and use state to surpass one of these nodes of a threshold value greater than a whole use state, if exist, then this node is increased a socket card;

Wherein,

This node use state is: Wherein, x ∈ V;

Whole use state is:

Wherein, x ∈ V, wherein,

V is the set of all nodes in the network, and | V| is n, and T is a time slot number, is assumed to be k, T＞0; I _xThe socket card quantity of representation node x; And U _{X, t}The channel number that representation node x has been configured in t time zone, and U _{X, t}≤ I _xAnd 0＜t≤T.

6. the method for distributed channel as claimed in claim 5 configuration, wherein, if these nodes on this routed path have been configured one or more transmission path, then give this or these transmission path one priority, then pay the utmost attention to the transmission path with this priority in the selection of this free channel.

7. the method for distributed channel as claimed in claim 5 configuration wherein, is used state at the channel according to these nodes, determine to add time division technique in the step of this or these free channel, with increase spendable should or these free channels.

8. one kind is applicable to the method that distributed channel disposes in the based on wireless mesh network, and wherein, this based on wireless mesh network comprises a plurality of nodes, and the method for this distributed channel configuration comprises:

According to a system requirement definition one flowmeter, this flowmeter is in order to set these nodes to preset flow and the direction of reception and the transmission of adjacent node;

According to a routed path and a bandwidth requirement, from these nodes, select the node of this routed path process, and determine a start node and a destination node;

According to this flow and direction, select the socket card quantity of these nodes; And

One or more free channel that uses according to the selective sequential from this destination node to this start node setting up this routed path, and meet this bandwidth requirement, and these adjacent nodes is not reused identical channel;

Wherein, should or these free channels be defined as this or these channel not in order to transmit, to receive or one of arbitrary state that disturbs, the selection of this free channel is not to reuse identical channel according within 3 jumps;

Wherein calculate with beneath operational formula for the socket card quantity of the required installation of each this node:

Wherein, n is the number of all these nodes in the network, and B is the total bandwidth of socket card, and T is these socket card number of time slots.

9. the method for distributed channel as claimed in claim 8 configuration, wherein, if these nodes on this routed path have been configured one or more transmission path, then give this or these transmission path one priority, then pay the utmost attention to the transmission path with this priority in the selection of this free channel.

10. the method for distributed channel as claimed in claim 8 configuration wherein, is used state at the channel according to these nodes, determine to add time division technique in the step of this or these free channel, with increase spendable should or these free channels.

11. a device that is applicable to distributed channel configuration in the based on wireless mesh network, wherein, this based on wireless mesh network comprises a plurality of nodes, and this device comprises:

Channel according to these nodes uses state, determines the module of one or more free channel between these adjacent nodes;

According to a routed path, select the node of this routed path process from these nodes, and from these nodes, determine the module of a start node and a destination node; And

These free channels that use according to the selective sequential from this destination node to this start node, setting up the module of this routed path,

Wherein, the selector of these free channels unification shortest path is by the path requirement, and the node adjacent with these do not reused identical channel;

Wherein, should or these free channels be defined as this or these channel not in order to transmit, to receive or one of arbitrary state that disturbs, the selection of this free channel is not to reuse identical channel according within 3 jumps.

12. device as claimed in claim 11 also comprises:

Pay the utmost attention to the module of the transmission path with a priority in the selection of this free channel, wherein, if these nodes on this routed path have been configured one or more transmission path, then give this or these this priority of transmission path.

13. device as claimed in claim 11 wherein, is using state according to the channel of these nodes, determine to add time division technique in the module of this or these free channel, with increase spendable should or these free channels.

14. a device that is applicable to distributed channel configuration in the based on wireless mesh network, wherein, this based on wireless mesh network comprises a plurality of nodes, and this device comprises:

According to a routed path, from these nodes, select these nodes of this routed path process, and from these nodes, determine the module of a start node and a destination node;

Channel according to these nodes uses state, determines the module of one or more free channel between these adjacent nodes;

According to a bandwidth requirement, select the module of the socket card quantity of these nodes of increase; And

These free channels that use according to the selective sequential from this destination node to this start node to be setting up this routed path, and meet the module of this bandwidth requirement;

Wherein, the selector of these free channels unification shortest path is by the path requirement, and the node adjacent with these do not reused identical channel;

Wherein, should or these free channels be defined as this or these channel not in order to transmit, to receive or one of arbitrary state that disturbs, the selection of this free channel is not to reuse identical channel according within 3 jumps;

Wherein, according to this bandwidth requirement, select the module of the socket card quantity of these nodes of increase to comprise according to this routed path and this bandwidth, carry out the configuration of channel, wherein, if dispose unsuccessfully, then judge whether to exist on this routed path to meet a node and use state to surpass one of these nodes of a threshold value greater than a whole use state, if exist, then this node is increased a socket card;

Wherein,

This node use state is:

Wherein, x ∈ V;

Whole use state is:

Wherein, x ∈ V, wherein,

V is the set of all nodes in the network, and | V| is n, and T is a time slot number, is assumed to be k, T＞0; I _xThe socket card quantity of representation node x; And U _{X, t}The channel number that representation node x has been configured in t time zone, and U _{X, t}≤ I _xAnd 0＜t≤T.

15. device as claimed in claim 14 also comprises:

Pay the utmost attention to the module of the transmission path with a priority in the selection of this free channel, wherein, if these nodes on this routed path have been configured one or more transmission path, then give this or these this priority of transmission path.

16. device as claimed in claim 14 wherein, is using state according to the channel of these nodes, determine to add time division technique in the module of this or these free channel, with increase spendable should or these free channels.

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