CN101572649A - Method and device for time slot allocation - Google Patents
Method and device for time slot allocation Download PDFInfo
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Abstract
The embodiment of the invention discloses a method and a device for time slot allocation. The method comprises the following steps: ensuring one radio link from a source node to a target node as a radio link for sending data preferably according to network topology information and time slot requirement information and allocating time slot to the radio link for sending data preferably, wherein in the step of allocating time slot to the radio link for sending data preferably comprises the specific steps: allocating continuous time slot for the source node or a middle node between the source node and the target node to ensure that the source node or the middle node between the source node and the target node can send data to the next node continuously. By adopting the time slot allocation method of the embodiment of the invention, frequent switching in the data transmitting process is reduced, bandwidth resources are saved, and space reusability is improved.
Description
Technical field
The present invention relates to communication technical field, particularly relate to a kind of slot allocation method and device.
Background technology
Wireless MESH network receives increasing concern recently as a kind of emerging radio network technique, in Wireless MESH network, comprises a plurality of nodes usually, and the mode by multi-hop between the node communicates.In network, there are one or more nodes directly to link to each other usually with cable network (as internet network, fixed line core network, mobile communication core network etc.), claim that these nodes are gateway node; Other node in the network then must just can have access to spider lines through gateway node by the multi-hop mode.
In Wireless MESH network, wireless channel is by all nodes sharing, the therefore chance that must provide a kind of shared mechanism to come to provide for each node access wireless channel, phase mutual interference when avoiding between the node communication.This shared mechanism promptly is a kind of multiple access access mechanism.In Wireless MESH network, mainly adopt two kinds of multiple access access mechanisms at present, a kind of is CSMA/CA (Carrier Sense MultipleAccess/Collision Avoidance, carrier sense multiple access/conflict is avoided) mechanism, another kind is TDMA (Time Division Multiple Access, time division multiple access an inserts) mechanism.Wherein CSMA/CA is a kind of mechanism based on competition, and the node in the network obtains access right to wireless channel by the mode of competition, and TDMA is a kind of mechanism based on scheduling, and the node in the network is access channel in the time slot of allocating in advance.
In Wireless MESH network based on TDMA mechanism, usually Radio Resource is divided the form of framing, every frame be one regular time length, a frame is divided into a plurality of time slots again.All nodes in the network all can only be in one or more time slots of allocating in advance access channel.For the node in the network distributes a kind of common method of access slot is centralized time slot allocation.
Centralised allocation is concentrated by certain node (as gateway node/root node) in the network and is the every other node distribution bandwidth in the network.Centralised allocation is suitable for all business and all is to and from gateway node, easily group of networks is made into tree topology, and wherein gateway node is as root node.Divide up link and down link according to the direction of business, promptly the business that mails to gateway is regarded as up link, the business that comes from gateway is regarded as down link.
Because Wireless MESH network is the network of a multi-hop, need between the node of apart from each other to communicate, and data forwarding can reduce the throughput of network in the multi-hop communication by the mode of multi-hop.Owing to transmit the loss of throughput of bringing, need in dispatching method, adopt space multiplexing technique in order to reduce usually.In the Wireless MESH network based on TDMA mechanism, so-called space multiplexing technique is meant: for certain time slot, spatially link that can the phase mutual interference can transmit simultaneously.Slot allocation method under the centralized dispatching mechanism in the Wireless MESH network has been proposed at present.
Yet existing slot allocation method is limited to improving network throughput; And the technology that has also requires node to receive and dispatch switching continually between adjacent time-slots when transmitting data, switches the time-delay of introducing and will consume a large amount of bandwidth resources and receive and dispatch between adjacent time-slots.
Summary of the invention
The problem that the embodiment of the invention will solve provides slot allocation method and device, switches continually when transmitting data to reduce node.
For achieving the above object, the embodiment of the invention proposes a kind of slot allocation method on the one hand, comprising:
Determine the Radio Link conduct preferential Radio Link that send data of a source node according to network topological information and time slot demand information to destination node;
Wireless link distribution time slot for described preferential transmission data, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
The embodiment of the invention proposes a kind of slot allocation apparatus on the one hand, comprising:
First selects module, is used for determining the Radio Link conduct preferential Radio Link that send data of a source node to destination node according to network topological information and time slot demand information;
The time slot allocation module, be used to the wireless link distribution time slot of the definite preferential transmission data of the described first selection module, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
The technical scheme of the embodiment of the invention has the following advantages:
Adopt the slot allocation method of the embodiment of the invention, by determining that successively source node is the preferential Radio Link that sends data to the Radio Link of destination node, and be the wireless link distribution continuous time slot of described preferential transmission data, reduce the frequent switching in the data transmission procedure, saved bandwidth resources.
Description of drawings
Fig. 1 is the method flow diagram of time slot allocation in the embodiment of the invention;
Fig. 2 is a tree topology tree schematic diagram in the embodiment of the invention;
Fig. 3 is the spatial reuse rate performance simulation result comparison diagram of method in uplink time slot distributes that embodiment of the invention method and HanBo propose;
Fig. 4 is the switching times performance simulation of method in uplink time slot distributes that propose of an embodiment of the invention method and HanBo comparison diagram as a result;
Fig. 5 is the spatial reuse rate performance simulation result comparison diagram that adopts jumping figure maximum node and jumping figure minimum node priority allocation in the embodiment of the invention in downlink time slots distributes;
Fig. 6 is a slot allocation apparatus structural representation in the embodiment of the invention.
Embodiment
Below in conjunction with drawings and Examples, be that example is described further the specific embodiment of the invention with Wireless MESH network based on the IEEE802.16 standard.
Can be based on the Wireless MESH network of IEEE802.16 standard with TDMA as the multiple access access mechanism, the topological tree structure is adopted in its centralized dispatching, the root node of topological tree is a gateway node, be called MESH BS (hereinafter to be referred as MBS, claim the MESH base station again), other nodes are called MESH SS (hereinafter to be referred as MSS, claiming the MESH subscriber station again).
The embodiment of the invention one provides a kind of slot allocation method, as shown in Figure 1, may further comprise the steps:
Step S101 determines the Radio Link conduct preferential Radio Link that send data of a source node to destination node according to network topological information and time slot demand information.
Before this step, need obtain network topological information and time slot demand information.Wherein, the time slot demand information is determined according to bandwidth demand information.Be specially:
MBS is by the uplink traffic demand information of each MSS of MSH-CSCH message collection.Up and the downstream that is each MSS then distributes bandwidth, will send to each MSS for the bandwidth information of the flow distribution of all MSS by MSH-CSCH message again; MBS can broadcast route topological information (burst profile is described in the burst that comprises each link) by MSH-CSCF message earlier before sending MSH-CSCH message; After each MSS receives MSH-CSCF and MSH-CSCH message, according to the route topological information, the burst descriptor of each link that obtain, each node is up and cycle of the bandwidth demand information of downstream, frame or can be used for information such as distributed time slot sum, by the time slot allocation algorithm determine each node the time need demand.
Such as, in Wireless MESH network centralized dispatching mechanism based on IEEE802.16, finish time slot allocation jointly by MBS (gateway node) and MSS, wherein, by the bandwidth demand information of all MSS in the MBS collection network, and, by centralized dispatching message (MSH-CSCH and MSH-CSCF) these information are sent to all MSS then for each MSS distributes bandwidth and generates tree topology, each MSS calculates the time slot demand that each node sends data according to the message of receiving.
Also comprise when determining the time slot demand information of each node: the time slot demand information that writes down each node.Each node all records the time slot demand of other node in the time slot demand of node self and the network, and the time slot demand of self and the time slot demand of other node are distinguished.In the process of distributing time slot, per minute is joined a time slot, and then the time slot demand information of each node all upgrades.Specifically comprise: the time slot demand that this time slot sends the node of data subtracts 1, and the time slot demand that receives the node of data increases 1; And the time slot demand that increases and subtract can further specifically be the data that are used to transmit which node.
Step S102, wireless link distribution time slot for described preferential transmission data, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
S102 illustrates to step:
For example: in Fig. 2, node 4 sends in the Radio Link of data to node 1 through node 2, if need 2 time slots to carry out the transmission of data, then at first distribute 2 continuous time slot to be used for node 4 and send data to node 2, and then distribute 2 continuous time slot to be used for node 2 and transmit data to node 1, and the data of transmitting are the data that node 4 sends to node 2.
In this step, carry out different disposal during specific to the time slot allocation of up link and down link:
In up link, as the preferential Radio Link that sends data, described source node obtains according to described network topological information to the jumping figure of destination node source node to the Radio Link that the time slot demand is arranged of destination node jumping figure minimum in the selection Radio Link.
In down link, as the preferential Radio Link that sends data, described source node obtains from described network topological information to the jumping figure of destination node source node to the Radio Link that the time slot demand is arranged of destination node jumping figure maximum in the selection Radio Link.
Fig. 2 is a kind of topological tree, and as shown in the figure, if source node and destination node are adjacent, then source node is 1 jumping to the jumping figure of destination node, for example: node 2 and node 3; If the data of the transmission of radio links from the source node to the destination node need be transmitted through a node, then source node is 2 jumpings to the destination node jumping figure, for example: node 4 and node 5; And the like, the jumping figure of node 6 is 3.In Fig. 2, node 2 is identical with node 3 jumping figures, and the jumping figure of node 4 and node 5 is also identical; When existing the identical node of a plurality of jumping figures available, determine the Radio Link of described preferential transmission data according to the precedence information of jumping figure same node point.For example: can adopt the information of energy unique identification node to carry out assisted Selection, for example the memory location of address of node sign, information even numbering etc.
In the assigning process of time slot, the jumping figure of each node is constant, because the time slot demand information needs constantly to upgrade in assigning process, therefore, after a chain time gap assigns, the jumping figure and the time slot demand information that need comprehensive node select the source node of jumping figure minimum to arrive the Radio Link of the Radio Link of destination node for preferential transmission data in the node that the time slot demand information is arranged successively.
In the present embodiment, in order further to improve the spatial reuse rate, for each time slot to be allocated, can also be according to the link interference principle, select Radio Link with described preferential transmission data, or, with the Radio Link of described preferential transmission data and the parallel link of the having determined link that do not have an interference as and the parallel parallel link that sends of Radio Link of described preferential transmission data.
Link interference principle in the present embodiment can comprise:
Node can not transmit and receive data simultaneously, and can not send data for simultaneously a plurality of nodes, can not receive the data of a plurality of nodes simultaneously;
When node sent data, other all neighbor nodes that then receive the node of described data can not receive data;
When node received data, other all neighbor nodes that then receive the node of data can not send data.
Be illustrated below in conjunction with accompanying drawing:
Fig. 2 provides a kind of topological tree, can comprise 6 nodes of numbering 1 to 6, and solid line is represented the valid data transmission link, and dotted line is represented interfering link.Wherein, node 1 is a root node, i.e. MESH base station (MBS), other node are MESH subscriber station (MSS).Wherein, the jumping figure of node 1 is 0, and the jumping figure of node 2 and node 3 is 1, and the jumping figure of node 4 and node 5 is 2, and the jumping figure of node 6 is 3.Tree-like route topological shown in Figure 2 is generated according to certain routing algorithm by MBS, and sends to all MSS by MSH-CSCF message.
Since MBS by each node of MSH-CSCH message collection the upstream bandwidth demand and by this message the bandwidth demand of all nodes is sent to each MSS.Easily the bandwidth demand of node is converted into the time slot demand by formula.For example:
Can according to the bandwidth demand information R of each node (bps), the speed C of the length τ (second) of wireless frame period T (second), a time slot and Radio Link (bps), calculate the time slot demand of each node in a frame respectively, computing formula is as follows:
Time slot demand information=R*T/ (C* τ);
Wherein " * " represents multiplication, "/" expression division operation; When described time slot demand information is not integer, to the processing that rounds up of described time slot demand.
Here adopt forms mode to describe the time slot demand information of each node, the time slot demand information of each node also can write down or store with the form beyond the form.Certainly, a certain node time slot demand information also can further be distinguished the time slot demand of the data that node oneself produces and need to transmit the time slot demand information of the data of other node.As described in Table 1, row and column is representation node all, and row has node 1 to node 6, shows node 1 to node 6, and (1,1) the lattice representation node 1 in the form is a root node, does not have the time slot demand; The value of (2, the 2) lattice in the form is 2, and the up direction of representation node 2 needs 2 time slots to send the data of self.Suppose that the ascending time slot demand except that node 1 is 0, the ascending time slot demand of other each node is 2.The form that is used to write down each node ascending time slot demand information is as shown in table 1.
Table 1 (ascending time slot demand schedule):
| Node | 1 | 2 | 3 | 4 | 5 | 6 |
| 1 | 0 | |||||
| 2 | 2 | |||||
| 3 | 2 | |||||
| 4 | 2 | |||||
| 5 | 2 | |||||
| 6 | 2 |
Each row and each row are for a node in the table 1.Because upstream data is distributed in each node during beginning, and do not comprise the data that needs are transmitted in each node, therefore in form, have only the time slot requirements non-zero (value that does not mark in the form all is set to 0) on the diagonal.
Wherein, in the process of distributing time slot, per minute is joined a time slot, all needs each node time slot demand information is upgraded.With table 1 is example, and the method for upgrading the time slot demand information is as follows:
The time slot demand that this time slot sends the node of data subtracts 1, and the time slot demand that receives the node of data increases 1; And the time slot demand that increases and subtract can further specifically be the data that are used to transmit which node.In some complicated topological trees, in the process of time slot allocation,, represent that then node transmits the required time slot demand of other node if the lattice beyond the diagonal in the form also have the time slot demand.For example: (2, the 3) lattice in the form have the time slot demand, and value is 2, and then identification nodes 2 needs the data of 2 time slot forward node 3.
Time slot allocation for up link:
When time slot allocation begins, at first determine the preferential Radio Link that sends data.From above-mentioned table 1 as can be seen, the node 2 of jumping figure minimum and node 3 all have data to need transmission, when existing the identical Radio Link of a plurality of jumping figures available, determine the Radio Link of described preferential transmission data according to the precedence information of described Radio Link source node, for example: can adopt the information of energy unique identification node to carry out assisted Selection, for example the memory location of address of node sign, information even numbering etc.When supposing that jumping figure is identical, can be according to the less node priority allocation time slot of node serial number, therefore, at first time slot, the data of transmission node 2 at first then, as can be seen from Figure 2, article one Radio Link that can transmit data is the up link of node 2, i.e. 1 the link from node 2 to node.The form of each node uplink time slot demand information of the record shown in the updating form 1 then, the time slot demand of the sending node of data in the link (node 2) subtracts 1, the time slot demand of the source node of these data adds 1 in the receiving node of data in the link (node 1), the value that is the first row secondary series position (1,2) in the form 1 increases by 1.The form of record time slot allocation result shown in the updating form 2 is set to 2 with second row, first column position (2,1) simultaneously, and expression node 2 is in the data (being the data that it produces itself) of the 1st time slot sending node 2.
Then, determine in first time slot, can to walk abreast and send other Radio Link of data.Transmission path in the search network is selected node 3,4,5, the up link of 6 correspondences, decision node 3,4,5, whether the up link of 6 correspondences is disturbed with the link existence of node 1, judges according to the link interference principle, obtains not having the Radio Link that other can walk abreast and send.
Equally, at second time slot, also have only the up link of node 2 correspondences can send data, other link can not send data.At the source node of the Radio Link of the preferential transmission data of selecting to the transmission path of destination node, the data of source node are transmitted to described destination node after all being transferred to next-hop node again, such as, the next-hop node of node 2 and node 3 is node 1 (MBS).
At the 3rd time slot, because the intact node 2 of continuous dispensing distributes time slot to node 1 required all, therefore, again according to the time slot demand information of current each node with have the jumping figure of the node of time slot demand to distribute nextly to have the transmission path of the data of the little source node of time slot demand and jumping figure to be the preferential Radio Link that sends data, the up link that can determine node 3 correspondences is as the preferential Radio Link that sends data, and the 3rd time slot that promptly distributes and the 4th time slot are used for the upstream data of transmission node 3.When selecting the link of other possibility parallel transmission data, according to the link interference principle, the corresponding up link of the up link of node 4 and node 5 correspondences and node 3 can mutual interference mutually, therefore can not the parallel transmission data, and the corresponding not mutual interference mutually of up link of the up link of node 6 correspondences and node 3, so the up link of the node 6 correspondences transmission data that can walk abreast.In some complicated topological networks, same distributed time slot may exist and the preferential parallel multi wireless links of Radio Link that sends data, whether all Radio Links that need judge whether equally in the selection course of follow-up link and select exist interference, all Radio Links that have only and selected do not exist when disturbing, and this link just can become the link that carries out the synchronized transmission data at this time slot.
According to the little prioritised transmission principle of the numbering in the precedence information of jumping figure same node point, the data of next preferential sending node 4, determine that node 4 is the preferential Radio Link that sends data to the Radio Link of node 1, therefore, at the 5th time slot and the 8th time slot, distribute 4 continuous time slot to be used for the data of transmission node 4, and in each concrete time slot, further be chosen in the parallel link that this time slot can walk abreast and send.
According to same method, the Radio Link that sends data that can walk abreast in other time slot can be determined one by one.
Distribute for uplink time slot, when the transmitting uplink data of all nodes behind MBS, time slot allocation finishes, time slot allocation result is as shown in table 2, wherein, row representation node, row have node 1 to node 6, row are represented time slot, time slot 1 is arranged to time slot 16, all transfer of data that promptly need to distribute 16 time slots node 2 could be arrived all MSS of node 6 arrive node 1 (that is: MBS), (2 in the form, 1) lattice representatives distributes time slot at the 1st, transmission be the data of node 2.Again for example: (3 in the form, 3) and (6,3) representative is at the 3rd link that distributes time slot to have two parallel conveys, the up direction data carried by data is respectively: node 3 up directions (being that node 3 is to node 1) send the data of self, the data of node 6 up directions (being that node 6 is to node 4) sending node 6.Again for example, (2,11) lattice representative in the form distributes time slot at the 11st, and up direction is the data of node 2 transmission nodes 5.
Table 2 (the uplink time slot allocation result of Fig. 2 topological structure):
| Node time slot | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 1 | ||||||||||||||||
| 2 | 2 | 2 | 4 | 4 | 5 | 5 | 6 | 6 | ||||||||
| 3 | 3 | 3 | ||||||||||||||
| 4 | 4 | 4 | 6 | 6 | ||||||||||||
| 5 | 5 | 5 | ||||||||||||||
| 6 | 6 | 6 |
For the superiority of the inventive method is described, under identical known conditions, the time slot demand that is topological tree and each node is all identical, adopts the best slot allocation method by proposition such as HanBo of City University of Hong Kong of performance in the existing time slot allocation technology to carry out time slot allocation, so that comparison.The time slot allocation result that the method that employing HanBo etc. proposes obtains is as shown in table 3, wherein, the row representation node, row are represented time slot, the numeral 1 that value in the form shows represents that certain node can send data (can't represent to send the affiliated node of data) in corresponding time slot.
Table 3 (the time slot allocation result that HanBo proposes):
| Node time slot | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 1 | ||||||||||||||||
| 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | ||||||||
| 3 | 1 | 1 | ||||||||||||||
| 4 | 1 | 1 | 1 | 1 | ||||||||||||
| 5 | 1 | 1 | ||||||||||||||
| 6 | 1 | 1 |
From table 2 and table 3 as can be seen, the scheduling length of the slot allocation method acquisition that the slot allocation method that this paper proposes and HanBo etc. propose is identical, all be 16 time slots, promptly the transmitting uplink data of all nodes to be arrived MBS, need 16 time slots altogether, this spatial reuse rate that these two kinds of methods acquisitions are described is suitable, and the Monte-Carlo Simulation experiment in Fig. 3 has also proved this point.But as can be seen from Table 3, in the slot allocation method that HanBo etc. propose, node is (as node 2, node 4) when transmitting data, whenever receive the data of a time slot, all in next time slot, transmit, cause node when transmitting data, frequently between adjacent time-slots, to receive and dispatch switching like this, and as can be seen from Table 2, the inventive method is when carrying out time slot allocation in the present embodiment, node is just transmitted after the data of receiving a plurality of time slots (present embodiment is 2 time slots), so switching times obviously reduces.In real system, the time-delay that the frequent switching between adjacent time-slots is introduced can consume a large amount of bandwidth resources.
In order to further specify the superiority of the inventive method in uplink time slot distributes, the spatial reuse rate and the forward node of various slot allocation methods are received and dispatched switching between adjacent time-slots when transmitting data number of times has carried out Monte-Carlo Simulation, simulation result is distinguished as shown in Figure 3 and Figure 4, and wherein each emulated data all is on average to be tried to achieve by 1000 times simulation result.As can be seen from Figure 3, distribute for uplink time slot, the best link system of selection of spatial reuse rate that the inventive method obtains in uplink time slot distributes and HanBo etc. is suitable.But as can be seen from Figure 4, the switching times of the slot allocation method that HanBo etc. propose is higher, and the switching times of the inventive method significantly reduces.
Distribute for downlink time slots:
In the present embodiment, the method that implementation method that downlink time slots distributes and uplink time slot distribute is similar, and main difference is the link selection principle that adopts and is used to write down each node time slot demand information all to concentrate on root node MBS.In downlink time slots distributed, the link selection principle of employing was that the high priority data of jumping figure maximum node distributes, and adopts the hop-by-hop transmission policy on transmission path.
Here adopt forms mode to describe the time slot demand information of each node, the time slot demand information of each node also can write down or store with the form beyond the form.Certainly, a certain node time slot demand information also can further be distinguished the time slot demand of the data that node oneself produces and need to transmit the time slot demand information of the data of other node.As described in Table 4, row and column is representation node all, and row has node 1 to node 6, shows node 1 to node 6, in the table 4 the 1st row representation node 1 is concentrated the data of node 2 to all nodes of node 6, and the data of each node of 6 all need two time slots to node 2 to node.
As shown in Figure 2, the descending time slot demand of supposing each node except that MBS equally also is 2 and since when beginning each node downlink data all concentrate among the MBS, the form that is used to write down each node descending time slot demand is as shown in table 4:
Table 4 (descending time slot demand schedule):
| Node | 1 | 2 | 3 | 4 | 5 | 6 |
| 1 | 0 | 2 | 2 | 2 | 2 | 2 |
| 2 | ||||||
| 3 | ||||||
| 4 | ||||||
| 5 | ||||||
| 6 |
Wherein, have only in the node 1 (MBS) and each node time slot corresponding demand non-zero (value that does not mark in the form all is set to 0).
The procedure declaration that downlink time slots is distributed is as follows:
When just beginning to distribute time slot,, therefore be preferably node 6 and distribute time slot because node 6 has time slot demand and jumping figure maximum.According to route topological information, node 6 needs to transmit through intermediary node 2 and node 4, can be preferably node 6 and distribute 6 continuous time slot.For first time slot, be 2 down link from node 1 to node.In the form shown in the table 4, revise the time slot demand of interdependent node then, to subtract 1 with node 6 time slot corresponding demands in the node 1 (in the form (1,6) value of position subtracts 1), and will add for 1 (value of (2,6) position adds 1 in the form) with node 6 time slot corresponding demands in the node 2.Record time slot allocation result's form is set simultaneously, as shown in table 5, the value of position in the form (1,1) is set to 6, expression node 1 is in the data of first time slot sending node 6.
Be chosen in other link that can walk abreast in first time slot and send then, have only MBS to have data to transmit during owing to beginning, the temporary transient free of data of other node can be transmitted, and therefore, at first time slot, does not have other link parallel transmission.
For second time slot,, determine that easily the preferential Radio Link that sends data is similarly from node 1 to node 2 down link because the data of node 6 are not transferred to node 6.Also determining not have other link easily in second time slot can parallel transmission.
The distribution of the 3rd and the 4th time slot and preceding two similar, to the 5th time slot, determine that easily the preferential Radio Link that sends data is similarly from node 4 to node 6 down link, and transmission is the data of node 6, when selecting the link of parallel transmission, the same data of considering the big node of priority allocation jumping figure, but from the topological tree of Fig. 2, find out easily, wherein node 5 sends the down link that all needs to arrive through node 1 node 2 with the data of the down link of node 4, according to disturbing principle, this link can mutual interference mutually with 6 the down link from node 4 to node, therefore this link can not parallel transmission, and from node 1 to node 3 down link and 6 not mutual interference mutually of down link from node 4 to node, so these two links can parallel transmission.We at the 5th time slot, have two nodes (node 1 and node 4) can send data as can be seen from table 5.
Distribute after the time slot of data of transmission node 6, distribute that next the Radio Link of time slot demand and node jumping figure maximum is arranged is the Radio Link of described preferential transmission data.There is identical jumping figure in node 4 with node 5, and the time slot demand is arranged all, determine the Radio Link of described preferential transmission data according to the precedence information of jumping figure same node point, the priority allocation time slot that node serial number is big in the present embodiment, so next jumps preferentially, and the link of transmission data is the respective links of transmission node 5 data.
After the same method, also can determine the distribution of other time slot, when the downlink data of all nodes all was transferred to corresponding node, descending time slot distributed end, and time slot allocation result is as shown in table 5.
Table 5 (the downlink time slots allocation result of Fig. 2 topological structure):
| Node time slot | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 1 | 6 | 6 | 3 | 3 | 5 | 5 | 4 | 4 | 2 | 2 | ||||||
| 2 | 6 | 6 | 5 | 5 | 4 | 4 | ||||||||||
| 3 | ||||||||||||||||
| 4 | 6 | 6 | ||||||||||||||
| 5 |
| 6 |
For the superiority of the link selection that adopts jumping figure maximum node data priority allocation in downlink time slots distributes is described, under the identical condition of topological tree and each node descending time slot demand, after the same method, time slot allocation result when obtaining easily to adopt the link selection principle that jumping figure minimum node high priority data distributes, as shown in table 6.
Table 6 (the time slot allocation result that the link selection principle of distributing according to jumping figure minimum node high priority data draws):
| Node time slot | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 1 | 2 | 2 | 3 | 3 | 4 | 4 | 5 | 5 | 6 | 6 | ||||||||
| 2 | 4 | 4 | 5 | 5 | 6 | 6 | ||||||||||||
| 3 | ||||||||||||||||||
| 4 | 6 | 6 | ||||||||||||||||
| 5 | ||||||||||||||||||
| 6 |
Comparison sheet 6 and table 5 can be found, adopting the scheduling length of the link selection principle of jumping figure minimum node high priority data distribution is 18, scheduling length greater than the link selection principle that adopts jumping figure maximum node data priority allocation, this spatial reuse rate that the former is described is lower, and transmitting identical data needs more time slot.
Performance difference when in downlink time slots distributes, adopting different link selection principle for further checking the inventive method, the spatial reuse rate performance when adopting two kinds of different link selection principles has been carried out Monte-Carlo Simulation, and simulation result is as shown in Figure 5.As can be seen from Figure 5, the method for the embodiment of the invention adopts the link selection principle of jumping figure maximum node data priority allocation can improve about 10% on spatial reuse rate performance in downlink time slots distributes.
In the above-described embodiments, by determining that successively source node is the preferential Radio Link that sends data to the Radio Link of destination node, and be the wireless link distribution continuous time slot of described preferential transmission data, reduced the frequent switching in the data transmission procedure, saved bandwidth resources.On the other hand, for each time slot to be allocated,, also further improved the spatial reuse rate by selecting parallel link.Simultaneously, time slot allocation for up link and down link adopts different processing methods, no matter be in up process, still in the descending process, under the prerequisite that guarantees the data normal transmission, avoid the frequent switching of node between transceive data to greatest extent, and improved the spatial reuse rate as much as possible.
The embodiment of the invention also provides a kind of device of time slot allocation, comprising:
First selects module 1, is used for determining the Radio Link conduct preferential Radio Link that send data of a source node to destination node according to network topological information and time slot demand information;
Time slot allocation module 3, be used to the described first wireless link distribution time slot of selecting the preferential transmission data that module 1 determines, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
This device also comprises:
Second selects module 5, be used to select the Radio Link of selecting the preferential transmission data that module 1 determines with described first, or, with the Radio Link of described preferential transmission data and the parallel link of the having determined link that do not have an interference as and the parallel parallel link that sends of Radio Link of described preferential transmission data.
Wherein time slot allocation module 3 comprises that also the parallel links that are used to the second selection module 5 to determine distribute time slot.
Wherein first select module 1 to comprise:
Up chooser module 11 is used for selecting the Radio Link conduct preferential Radio Link that send data that time slot demand arranged of Radio Link source node to destination node jumping figure minimum.
Wherein first select module 1 to comprise:
Descending chooser module 13 is used for selecting the Radio Link conduct preferential Radio Link that send data that time slot demand arranged of Radio Link source node to destination node jumping figure maximum.
Further can also comprise
First is provided with submodule 15: be used to be provided with the precedence information of the source node of the identical Radio Link of jumping figure, determine the Radio Link of described preferential transmission data for described up chooser module 11.
Second is provided with submodule 17: be used to be provided with the precedence information of the destination node of the identical Radio Link of jumping figure, determine the Radio Link of described preferential transmission data for described descending chooser module 13.
The device that adopts present embodiment to provide satisfies in the time slot allocation process, and up link is carried out different processing with down link, has reduced the frequent switching of node between transceive data, and has improved the spatial reuse rate.Optimized the systematic function of network.
Need to prove, adopt in the wireless network of centralized dispatching mechanism at some other, also can collect the bandwidth demand information of each node M SS by root node MBS, time slot demand information according to each node of bandwidth demand information calculations, distribute time slot according to the topology information of network and the time slot demand information of each node, then allocation result is sent to other node M SS, MSS directly carries out the transmission of data according to this allocation result.Therefore in these networks, the method for the embodiment of the invention also can only be used for root node to realize time slot allocation.
It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, module in the accompanying drawing or flow process might not be that enforcement the present invention is necessary.
It will be appreciated by those skilled in the art that the module in the device among the embodiment can be distributed in the device of embodiment according to the embodiment description, also can carry out respective change and be arranged in the one or more devices that are different from present embodiment.The module of the foregoing description can be merged into a module, also can further split into a plurality of submodules.
The scheme of the content record of claim also is the protection range of the embodiment of the invention.
Through the above description of the embodiments, those skilled in the art can be well understood to the present invention and can realize by hardware, also can realize based on such understanding by the mode that software adds necessary general hardware platform, technical scheme of the present invention can embody with the form of software product, it (can be CD-ROM that this software product can be stored in a non-volatile memory medium, USB flash disk, portable hard drive etc.) in, comprise that some instructions are with so that a computer equipment (can be a personal computer, server, the perhaps network equipment etc.) carry out the described method of each embodiment of the present invention.
The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be looked protection scope of the present invention.
Claims (13)
1, a kind of slot allocation method is characterized in that, may further comprise the steps:
Determine the Radio Link conduct preferential Radio Link that send data of a source node according to network topological information and time slot demand information to destination node;
Wireless link distribution time slot for described preferential transmission data, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
2, the method for claim 1 is characterized in that, also comprises:
According to the link interference principle, select Radio Link with described preferential transmission data, or, with the Radio Link of described preferential transmission data and the parallel link of the having determined link that do not have an interference as and the parallel parallel link that sends of Radio Link of described preferential transmission data.
3, method as claimed in claim 2 is characterized in that, described link interference principle comprises:
Node can not transmit and receive data simultaneously, and can not send data for simultaneously a plurality of nodes, can not receive the data of a plurality of nodes simultaneously;
When node sent data, other all neighbor nodes that then receive the node of described data can not receive data;
When node received data, other all neighbor nodes that then receive the node of data can not send data.
4, as the arbitrary described method of claim 1 to 3, it is characterized in that, described according to network topological information and time slot demand information determine a source node to the Radio Link of destination node as the preferential Radio Link that sends data, be specially:
In up link, as the preferential Radio Link that sends data, described source node obtains according to described network topological information to the jumping figure of destination node source node to the Radio Link that the time slot demand is arranged of destination node jumping figure minimum in the selection Radio Link.
5, method as claimed in claim 4 is characterized in that, also comprises:
When existing the identical Radio Link of a plurality of jumping figures available, determine the Radio Link of described preferential transmission data according to the precedence information of described Radio Link source node.
6, as right 1 to 3 arbitrary described method, it is characterized in that, described according to network topological information and time slot demand information determine a source node to the Radio Link of destination node as the preferential Radio Link that sends data, be specially:
In down link, as the preferential Radio Link that sends data, described source node obtains from described network topological information to the jumping figure of destination node source node to the Radio Link that the time slot demand is arranged of destination node jumping figure maximum in the selection Radio Link.
7, method as claimed in claim 6 is characterized in that, also comprises:
When existing the identical Radio Link of a plurality of jumping figures available, determine the Radio Link of described preferential transmission data according to the precedence information of described Radio Link destination node.
8, a kind of slot allocation apparatus is characterized in that, comprising:
First selects module, is used for determining the Radio Link conduct preferential Radio Link that send data of a source node to destination node according to network topological information and time slot demand information;
The time slot allocation module, be used to the wireless link distribution time slot of the definite preferential transmission data of the described first selection module, wherein be specially for the wireless link distribution time slot of described preferential transmission data: be source node, perhaps, intermediate node between source node and the destination node distributes continuous time slot, so that source node, perhaps, the intermediate node between source node and the destination node can send data continuously to next node.
9, device as claimed in claim 8 is characterized in that, also comprises:
Second selects module, be used to select the Radio Link of selecting the preferential transmission data that module determines with described first, or, with the Radio Link of described preferential transmission data and the parallel link of the having determined link that do not have an interference as and the parallel parallel link that sends of Radio Link of described preferential transmission data.
10, device as claimed in claim 8 is characterized in that, described first selects module to comprise:
Up chooser module is used for selecting the Radio Link conduct preferential Radio Link that send data that time slot demand arranged of Radio Link source node to destination node jumping figure minimum.
11, device as claimed in claim 10 is characterized in that, described first selects module also to comprise:
First is provided with submodule: be used to be provided with the precedence information of the source node of the identical Radio Link of jumping figure, determine the Radio Link of described preferential transmission data for described up chooser module;
12, device as claimed in claim 8 is characterized in that, described first selects module to comprise:
Descending chooser module is used for selecting the Radio Link conduct preferential Radio Link that send data that time slot demand arranged of Radio Link source node to destination node jumping figure maximum.
13, device as claimed in claim 12 is characterized in that, described first selects module to comprise:
Second is provided with submodule: be used to be provided with the precedence information of the destination node of the identical Radio Link of jumping figure, determine the Radio Link of described preferential transmission data for described descending chooser module.
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| CNA2008100938295A CN101572649A (en) | 2008-04-30 | 2008-04-30 | Method and device for time slot allocation |
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| CNA2008100938295A CN101572649A (en) | 2008-04-30 | 2008-04-30 | Method and device for time slot allocation |
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102714871A (en) * | 2010-01-22 | 2012-10-03 | 西门子公司 | Method for associating time slots with links between network nodes of a wireless interconnected network |
| CN104378840A (en) * | 2014-12-01 | 2015-02-25 | 苏州市欧博锐自动化科技有限公司 | Method for temporary direct communication between indirect communication nodes |
| CN104717154A (en) * | 2015-02-27 | 2015-06-17 | 华为技术有限公司 | Method and device for sending data package |
| WO2018010618A1 (en) * | 2016-07-12 | 2018-01-18 | 华为技术有限公司 | Method and device for acquiring path information about data packet |
| CN110661589A (en) * | 2019-09-27 | 2020-01-07 | 中国航空无线电电子研究所 | Time slot allocation scheduling method based on switched time-triggered network |
| CN111263443A (en) * | 2018-11-30 | 2020-06-09 | 海能达通信股份有限公司 | Dynamic subframe allocation method and device |
| CN112600732A (en) * | 2020-12-09 | 2021-04-02 | 广州技象科技有限公司 | Data transmission method, device and system based on data margin and storage medium |
| CN113785538A (en) * | 2019-05-03 | 2021-12-10 | 微芯片技术股份有限公司 | Media access for time sensitive and best effort data packets and related systems, methods and devices |
| CN114126065A (en) * | 2021-11-25 | 2022-03-01 | 湖南智领通信科技有限公司 | CSMA (Carrier sense multiple Access) -based time domain radio resource scheduling method and device |
| CN114585043B (en) * | 2022-03-25 | 2023-07-21 | 电子科技大学 | Routing method, device, computer equipment and storage medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102714871A (en) * | 2010-01-22 | 2012-10-03 | 西门子公司 | Method for associating time slots with links between network nodes of a wireless interconnected network |
| CN104378840A (en) * | 2014-12-01 | 2015-02-25 | 苏州市欧博锐自动化科技有限公司 | Method for temporary direct communication between indirect communication nodes |
| CN104717154A (en) * | 2015-02-27 | 2015-06-17 | 华为技术有限公司 | Method and device for sending data package |
| CN104717154B (en) * | 2015-02-27 | 2018-10-09 | 华为技术有限公司 | A kind of method and device of transmission data packet |
| WO2018010618A1 (en) * | 2016-07-12 | 2018-01-18 | 华为技术有限公司 | Method and device for acquiring path information about data packet |
| US11240164B2 (en) | 2016-07-12 | 2022-02-01 | Huawei Technologies Co., Ltd. | Method for obtaining path information of data packet and device |
| CN111263443A (en) * | 2018-11-30 | 2020-06-09 | 海能达通信股份有限公司 | Dynamic subframe allocation method and device |
| CN113785538A (en) * | 2019-05-03 | 2021-12-10 | 微芯片技术股份有限公司 | Media access for time sensitive and best effort data packets and related systems, methods and devices |
| CN113785538B (en) * | 2019-05-03 | 2024-04-02 | 微芯片技术股份有限公司 | Media access for time-sensitive and best effort data packets and related systems, methods and devices |
| CN110661589B (en) * | 2019-09-27 | 2021-04-23 | 中国航空无线电电子研究所 | Time slot allocation scheduling method based on switched time-triggered network |
| CN110661589A (en) * | 2019-09-27 | 2020-01-07 | 中国航空无线电电子研究所 | Time slot allocation scheduling method based on switched time-triggered network |
| CN112600732A (en) * | 2020-12-09 | 2021-04-02 | 广州技象科技有限公司 | Data transmission method, device and system based on data margin and storage medium |
| CN114126065A (en) * | 2021-11-25 | 2022-03-01 | 湖南智领通信科技有限公司 | CSMA (Carrier sense multiple Access) -based time domain radio resource scheduling method and device |
| CN114126065B (en) * | 2021-11-25 | 2024-09-13 | 湖南智领通信科技有限公司 | CSMA-based time-domain wireless resource scheduling method and device |
| CN114585043B (en) * | 2022-03-25 | 2023-07-21 | 电子科技大学 | Routing method, device, computer equipment and storage medium |
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