Summary of the invention
For overcoming available data dispatching method bandwidth usage rate variance and the incomplete defective of scheduling mechanism, the present invention proposes to support in a kind of wireless mesh network (MESH) data scheduling device and the method for service quality.
According to an aspect of the present invention, propose a kind of data scheduling device that wireless mesh network (MESH) is supported service quality that is used for, comprised schedule level one device that is positioned at destination node and the second-level dispatching device that is positioned at source node; Said schedule level one device comprises professional class manager; Scheduling queue selector I, transmission mode selector, bandwidth allocator I and user bandwidth counter; Said second-level dispatching device comprises scheduling queue selector II, bandwidth allocator II and data mapper;
Wherein, in the said schedule level one device, when being used to receive the MSH-DSCH_REQ of source node transmission, said professional class manager request is ranked according to type of service; Said scheduling queue selector I selects the request queue that will dispatch from service queue; Said bandwidth allocator I comes the virtual assigned bandwidth according to traffic performance and professional QoS parameter; Said transmission mode selector provides according to current channel conditions and connects corresponding modulation coding mode; Said user bandwidth counter will be distributed to same user's discontinuous bandwidth and merge into continuous bandwidth, and the schedule level one result is generated MSH-DSCH_GRANT message send to source node;
Wherein, in the said second-level dispatching device, the bandwidth region and the size of distributing in the MSH-DSCH_GRANT message of said scheduling queue selector II according to the destination node transmission, the business of selection priority scheduling from service queue; Said bandwidth allocator II connects maximum/minimum traffic volume that pairing QoS parameter calculates this frame according to difference, and the differentiated service grade is dispatched business by frame; Said data mapper sends to physical layer with the data of dispatching out, is transferred to destination node.
Wherein, said source node and said destination node connect through the three-way handshake process of MSH-DSCH message.
According to a further aspect in the invention, proposed a kind of data dispatching method that wireless mesh network (MESH) is supported service quality that is used for, having comprised:
Step 10), destination node utilize professional class manager that the different business request is arranged according to bandwidth request deadline according to the MSH-DSCH_REQ that source node sends;
Step 20), the scheduling queue selector I of destination node distinguishing from service queue the data of selection scheduling;
Step 30), the bandwidth allocator I of destination node comes the virtual assigned bandwidth according to traffic performance and professional QoS parameter;
Step 40), the transmission mode selector of destination node is according to the channel quality status that connects, for the user confirms modulation coding mode:
Step 50), the user bandwidth counter of the destination node discontinuous bandwidth that will distribute to same user merges into continuous bandwidth, and the schedule level one result generated MSH-DSCH_GRANT message send to source node;
Step 60), distribution bandwidth region and size in the scheduling queue selector II of the source node MSH-DSCH-GRANT message of sending according to destination node, from service queue, select the business of priority scheduling;
Step 70), the bandwidth allocator II of source node connects maximum/minimum traffic volume that pairing QoS parameter calculates this frame according to difference; The differentiated service grade is dispatched business by frame; Data mapper sends to physical layer with the data of dispatching out, is transferred to destination node.
Wherein, step 20) also comprise: the needed bandwidth UGS_size of statistics UGS service request; When the UGS formation is sky, select the scheduling queue of rtS, the needed bandwidth RTS_size of statistics rtS service request; When processing rtS service queue is sky, select the professional scheduling queue of nrtS, the needed bandwidth NRTS_size of statistics nrtS service request.
Wherein, step 30) also comprise: add up all professional bandwidth summations of being asked, obtain available time slot, be used to distribute bandwidth according to the bandwidth summation; Wherein, Use allocation strategy to be UGS traffic assignments bandwidth based on fixed cycle GRANT INTERVAL poll; The algorithm that adopts fixed-bandwidth to distribute is a rtS traffic assignments bandwidth, is nrtS traffic assignments bandwidth according to the descending order of Min_reserve_rate in the QoS parameter.
According to another aspect of the invention, proposed a kind of data dispatching method that wireless mesh network (MESH) is supported service quality that is used for, having comprised:
The MSH-DSCH_REQ that step 10), destination node send according to source node arranges the different business request deadline according to bandwidth request;
Step 20), destination node distinguishing from service queue the data of selection scheduling;
Step 30), destination node comes the virtual assigned bandwidth according to traffic performance and professional QoS parameter;
Step 40), destination node is according to the channel quality status that connects, for the user confirms modulation coding mode:
Step 50), the destination node discontinuous bandwidth that will distribute to same user merges into continuous bandwidth, and the schedule level one result generated MSH-DSCH_GRANT message send to source node;
Step 60), distribution bandwidth region and size in the source node MSH-DSCH_GRANT message of sending according to destination node, from service queue, select the business of priority scheduling;
Step 70), source node connects maximum/minimum traffic volume that pairing QoS parameter calculates this frame according to difference, the differentiated service grade is dispatched business by frame, and the data of dispatching out are sent to physical layer, is transferred to destination node.
Through using the present invention, use two-level scheduler mechanism, optimized bandwidth availability ratio, guaranteed the priority under the prerequisite of considering professional service quality.
Embodiment
Be described in detail supporting the data scheduling device and the method for service quality in a kind of wireless mesh network provided by the invention (MESH) below in conjunction with accompanying drawing and specific embodiment.
Fig. 1 illustrates the structure of data scheduler according to an embodiment of the invention; As shown in Figure 1; The invention provides a kind of data scheduling device that wireless mesh network (MESH) is supported service quality that is used for, this data scheduling device comprises the two-level scheduler device that is positioned at source node and destination node.Wherein, the schedule level one device that is positioned at destination node comprises professional class manager, scheduling queue selector I, transmission mode selector, bandwidth allocator I and user bandwidth counter.The second-level dispatching device that is positioned at source node comprises scheduling queue selector II, bandwidth allocator II and data mapper.
In the schedule level one device of destination node, professional class manager is used for when destination node is received the MSH-DSCH_REQ of source node transmission, request being ranked according to a definite sequence according to different business types.Wherein, MSH-DSCH_REQ (mesh distributed schedule request IE) is the request element in the DSCH message in the collaborative distributed MESH network three-way handshake, and detailed structure is seen IEEE802.16 agreement MSH-DSCH message format.Wherein, the form reqIE in the agreement does not comprise the qos restriction on the parameters, and the application joins the qos parameter among this reqIE in order to support qos.Source node and destination node are that the three-way handshake process through MSH-DSCH message connects and guarantees service quality.In another embodiment, professional class manager is arranged the formation of different service types according to bandwidth request according to the MSH-DSCH_REQ that source node sends deadline from short to long.In yet another embodiment; Source node possibly include multiple business according to the own service demand to the MSH-DSCH_REQ request that destination node sends; Have a plurality of IE, the professional class manager of destination node is divided into a plurality of formations according to the different service types of asking among the reqIE with IE.
In the schedule level one device of destination node, scheduling queue selector I selects the request queue that will dispatch from service queue according to certain strategy.Wherein, Pending business object comprises unsolicited grant service (unsolicited grant service; UGS), real time business (real-time service; RtS), non-real-time service (non real-time service, nrtS), destination node utilize scheduling queue selector I distinguishing from three formations the data of selection scheduling.In another embodiment, the scheduling queue selector I of destination node selects the reqIE formation of priority scheduling according to the priority of the different reqIE formations that receive.
In the schedule level one device of destination node, bandwidth allocator I is to different business characteristic and QoS parameter virtual assigned bandwidth that should business.Wherein, bandwidth allocator I mainly is through the differentiated service grade, according to the service priority different scheduling strategy that uses in order from high to low source node is distributed amount of bandwidth.In another embodiment, bandwidth allocator I is according to the reqIE formation virtual assigned bandwidth of selecting.
In the schedule level one device of destination node, transmission mode selector provides according to current selected channel transmitted situation and connects corresponding modulation coding mode, supplies it to carry out data bandwidth and physical slot by time conversion calculations.Wherein, transmission mode selector is that the generation of bandwidth allocator I and MSH-GRANT message provides and is connected corresponding modulation coding mode.In another embodiment, transmission mode selector is confirmed the suitable modulating coded system according to user's under connecting channel quality status for the user.
In the schedule level one device of destination node; After having distributed bandwidth for every connection; The discrete bandwidth that the user bandwidth counter will be distributed to same user is merged into and is continuous bandwidth, and the schedule level one result is generated MSH-DSCH_GRANT message sends to source node.Wherein, (mesh distributed schedule grant IE (from granter to requester) is the mandate element in the DSCH message in the collaborative distributed MESH network three-way handshake to MSH-DSCH_GRANT, and detailed structure is seen IEEE802.16 agreement MSH-DSCH message format.Equally, the form reqIE in the agreement does not comprise the qos restriction on the parameters, and the application joins the qos parameter among this reqIE in order to support qos.Wherein, the user bandwidth counter associates connecting with its affiliated user, the discrete bandwidth of distributing to same user is merged into be continuous bandwidth, the schedule level one result is generated MSH-DSCH_GRANT message send to source node.In another embodiment; The user bandwidth counter is done a statistics with the bandwidth of bandwidth allocator I virtual assigned; The discontinuous bandwidth of distributing to same user is converted into continuous bandwidth, generates MSH-DSCH_GRANT according to the final result of exporting and reply to source node.And source node is according to MSH-DSCH_GRANT (from granter to reques ter) generation MSH-DSCH_GRANT (the from requester to granter of destination node; In order to distinguish with the message of destination node transmission, this message is called MSH-DSCH_CONFIRM message) confirm.
In the second-level dispatching device of source node, scheduling queue selector II uses certain strategy from service queue, to select the business of priority scheduling according to distribution bandwidth region and size in the MSH-DSCH_GRANT message of destination node transmission.Wherein, scheduling queue selector II uses certain strategy from the different business formation, to select the business of priority scheduling according to the characteristic of different business.In another embodiment, scheduling queue selector II classifies the different business data on upper strata, forms the scheduling queue of data.
In the second-level dispatching device of source node, bandwidth allocator II connects pairing QoS parameters through different, calculates the maximum/minimum traffic volume of this frame institute, and the differentiated service grade is pursued frame business is dispatched.Wherein, bandwidth allocator II carries out the two-wheeled scheduling according to the result of schedule level one to sent miscellaneous service, for each targeted customer's service flow is distributed bandwidth.Simultaneously, bandwidth allocator II adjusts the bandwidth that comprises among the grantIE according to the data dispatch formation of itself, sends the high business of priority earlier.
In the second-level dispatching device of source node, data mapper sends to physical layer with ready frame data in the data of dispatching out, is transferred to destination node.In another embodiment, the data map that data mapper will be sent waits to be sent to physical layer.
Further, continue to specify the concrete realization of device of the present invention and operation method thereof with reference to figure 1.
Step S1; The MSH-DSCH_REQ that destination node sends according to the source node that receives; Utilize the professional class manager will be for the request of UGS, rtS, three kinds of different business of nrtS according to (request the time of advent+time-delay) arrangement from short to long bandwidth request deadline according to the content in the request, the time, the shortest business be arranged in the top of formation.Step S2, for pending UGS, rtS, three formation business of nrtS, the scheduling queue selector I of destination node distinguishing from three formations the data of selection scheduling.Step S3, bandwidth allocator I adopts the dispatching algorithm of differentiated service grade, dispatches according to UGS, rtS, the nrtS priority different scheduling strategy that uses in order from high to low.Step S4, the transmission mode selector of destination node is according to user's under connecting channel quality status, for the user confirms the suitable modulating coded system.Step S5 utilizes bandwidth allocator I to associate connecting with its affiliated user, distributes the statistics of bandwidth to add up based on the user.Step S6 generates MSH-DSCH_GRANT with the schedule level one result and replies to source node.Step S7, the bandwidth allocator II of source node calculates available bandwidth bw_size according to the MSH-DSCH_GRANT that receives, and equity miscellaneous service to be sent carries out allocated bandwidth.
In step S1, what carry out that this operation can guarantee to dispatch at first is the data the highest to delay requirement.Because it is UGS has relatively high expectations to real-time, therefore regularly arranged according to FIFO (first in first out, First In First Out).The rtS business is arranged according to expired time from short to long, and the nrtS business makes three formations wait for the processing of scheduling queue selector I according to the descending arrangement of rate requirement in the QoS parameter.
Further, as shown in Figure 2 with reference to figure 2, in step S2, take turns in dispatching cycle the business of using following steps S21-S24 to come selection scheduling every:
Step S21 selects the professional scheduling queue of UGS, the needed bandwidth UGS_size of statistics UGS service request.Because it requires than higher real-time, therefore to the formation of UGS service request, it is not empty needing only formation, with regard to priority scheduling.Consider that the professional bandwidth usage of UGS is little, the scheduling UGS that therefore tries one's best is professional, also can not influence other business.
Step S23 when the UGS formation is sky, selects the scheduling queue of rtS, the needed bandwidth RTS_size of statistics rtS service request.A maximum continuous is set handles the professional number MAX_rtS_DEAL of rtS, scheduling rtS is professional, till the professional quantity of the rtS that handles reaches upper bound MAX_rtS_DEAL.
Step S24 when processing rtS service queue is sky, selects the professional scheduling queue of nrtS, the needed bandwidth NRTS_size of statistics nrtS service request.
In step S3, particularly, following steps S31-S35:
Step S31 adds up all professional bandwidth summations of being asked, SUM_size=UGS_size+RTS_size+NRTS_size.
Step S32, the summation SUM_size according to bandwidth on demand obtains available time slot, is used to distribute bandwidth.
Step S33 is UGS traffic assignments bandwidth, and it is used the allocation strategy based on fixed cycle GRANTINTERVAL poll.Because the bandwidth demand of UGS business is less, therefore under normal circumstances, a dispatching cycle should be complete the service dispatching in the UGS formation.So just be unlikely to make rtS and nrtS professional hungry to death.When the UGS business sharply increases, possibly cause rtS or nrtS business can not obtain scheduling.Because the priority of UGS business is the highest, the situation that rtS that therefore causes or nrtS business can not get dispatching is also in the tolerable scope.
Step S34 is rtS traffic assignments bandwidth, the algorithm that adopts fixed-bandwidth to distribute.The every wheel when dispatching, I selects request to be scheduled by the scheduling queue selector.When dispatching the request of rtS business at every turn; Under the default situations; The recipient can distribute according to service quality lower limit bandwidth (Min_reserve_rate), when new MSH-DSCH_REQ request is arranged on the service flow, adjusts the distribution amount of bandwidth according to bandwidth on demand;, presses bandwidth on demand upper limit allocated bandwidth when surpassing service quality upper limit bandwidth, otherwise by request bandwidth allocation.When network over loading, can cause bandwidth to be distributed inadequately, at this moment, bandwidth allocator I distributes remaining bandwidth to give this overdue service flow, if the service flow that is down to the wire in addition is not assigned with bandwidth, then when next round is dispatched, at first distributes bandwidth for this service flow.
Step S35, professional for nrtS, in the scheduling queue, to the nrtS business according to the descending sequence arrangement of Min_reserve_rate in the QoS parameter.
In step S4, in one embodiment, can operate as follows particularly:
Step S41 judges current channel quality status;
Step S42, if channel is relatively poor, then signal is prone to make mistakes, and adopts stronger low-order-modulated (like BPSK two-phase PSK, QPSK QPSK) and the low rate coding of robustness, guarantees certain error rate requirement, otherwise, change step S43 over to;
Step S43, if channel is better, then signal is more stable, adopts to adapt to high order modulation (like the 64-QAM quadrature amplitude modulation) and the high-rate coded spectrum efficiency that improves that high data rate requires.
In step S5; As shown in Figure 3, the business that is based on during owing to bandwidth allocator I virtual assigned bandwidth connects, so distribution result possibly be discontinuous fragment; Through the user bandwidth counter; Discontinuous bandwidth through statistics, is merged into continuous bandwidth, as the input of MSH-DSCH_GRANT.That is to say; Because bandwidth allocator I distributes the bandwidth that causes each user to distribute discontinuous according to connection,, in the user bandwidth counter, can all users' available bandwidth be redistributed for making each user's available bandwidth continuous; Make user 1 account for the first of available bandwidth; User 2 accounts for second portion, by that analogy, the size of the shared bandwidth of each user distribute for its each service flow that bandwidth adds up with.
In step S7, the bandwidth allocator II of source node calculates available bandwidth bw_size according to the MSH-DSCH_GRANT that receives, equity miscellaneous service to be sent carries out allocated bandwidth.Comprise following operating procedure particularly:
Step S71, all the UGS data queues in the poll buffer memory, according to available bandwidth bw_size, UGS is professional for the scheduling of the beginning first round.
Step S72 obtains the QoS parameter in this connection, calculates the maximum traffic volume of this connection.Wherein for the calculating of maximum traffic volume, with the mode of sliding window, the initial moment is write down transmitting time; Each traffic volume of sending the record that finishes adds up, and will overflow up to traffic volume, and the frame number of perhaps initial moment record will overflow; Then upgrading transmitting time is current frame number, and traffic volume is 0; Write down for the first time delivery time and should be and find that this service flow has data to need to send for the first time, otherwise possibly cause the traffic volume calculated value excessive.Concrete computing formula is following:
(this frame) maximum traffic volume=maximum reserved rate * (present frame frame number-last registration frame number) * frame duration-sent data volume.(being applicable to the calculating of all maximum traffic volumes)
Step S73 according to the traffic volume of this frame, dispatches out data, and in available bandwidth bw_size, deducts the size of data that this is dispatched out, calculates remaining bandwidth left_size.
Step S74 utilizes the physical mappings device with the UGS data of dispatching out, generates MACPDU (Protocal Data Uint), and is mapped to the physical layer transmission.
Step S75, if left_size>0, poll rtS service queue then, first round scheduling r tS is professional, find out professional apart from expired time less than all rtS of T_reserved maximum retention time (can be provided with) according to the qos parameter, and mark.
Step S76 obtains the maximum speed that keeps of QoS parameter in this connection, calculates the maximum traffic volume of this connection, and traffic volume is as above calculated.
Step S77 calculates the min{ remaining bandwidth, maximum traffic volume }, dispatch out the data of corresponding size, and in available bandwidth bw_size, deduct the size of data that this is dispatched out, calculate remaining bandwidth left_size.
Step S78 utilizes the physical mappings device with the rtS data of dispatching out, generates MACPDU (Protocal Data Uint), and it is to be sent to be mapped to physical layer etc.
Step S79, if left_size>0, poll nrtS service queue then, nrtS is professional in first round scheduling, and mark.
Step S710 obtains the maximum speed that keeps of QoS parameter in this nrts connection, calculates the maximum traffic volume of this connection.
Step S711 calculates the min{ remaining bandwidth, maximum traffic volume }, dispatch out the data of corresponding size, and in available bandwidth bw_size, deduct the size of data that this is dispatched out, calculate remaining bandwidth left_size.
Step S712 utilizes the physical mappings device with the nrtS data of dispatching out, generates MAC PDU (Protocal Data Uint), and it is to be sent to be mapped to physical layer etc.
Step S713 if scheduling rtS business then second is taken turns in left_size>0, finds out the connection that mark is crossed from the rtS service queue.
Step S714 obtains the minimum reserved rate of the QoS parameter in this connection, calculates the minimum traffic volume of this connection.Concrete computing formula is following:
(this frame) minimum traffic volume=minimum reserved rate * (present frame frame number-last registration frame number) * frame duration-sent data volume.(being applicable to the calculating of all minimum traffic volumes)
Step S715 calculates the min{ remaining bandwidth, minimum traffic volume }, dispatch out the data of corresponding size, and in available bandwidth bw_size, deduct the size of data that this is dispatched out, calculate remaining bandwidth left_size.
Step S716 utilizes the physical mappings device with the rtS data of dispatching out, generates MACPDU (Protocal Data Uint), and it is to be sent to be mapped to physical layer etc.
Step S717 if scheduling nrtS business then second is taken turns in left_size>0, finds out the connection that mark is crossed from the nrtS service queue.
Step S718 obtains the maximum speed that keeps of QoS parameter in this nrts connection, calculates the minimum traffic volume of this connection.
Step S719 calculates the min{ remaining bandwidth, minimum traffic volume }, dispatch out the data of corresponding size, and in available bandwidth bw_size, deduct the size of data that this is dispatched out, calculate remaining bandwidth left_size.
Step S720 utilizes the physical mappings device with the nrtS data of dispatching out, generates MACPDU (Protocal Data Uint), and it is to be sent to be mapped to physical layer etc.
In yet another embodiment of the present invention; The data dispatching method of supporting service quality in a kind of wireless mesh network (MESH) is provided; Be appreciated that; Said method depends on concrete device and device in implementation procedure, and in yet another embodiment of the present invention, the realization of this method can be realized supporting in the wireless mesh network (MESH) data dispatch of service quality by user node and source node according to following flow process.
Generally speaking; This method comprises: step S1; The MSH-DSCH_REQ that destination node sends according to the source node that receives; Will be according to the content in the request for the request of UGS, rtS, three kinds of different business of nrtS according to bandwidth request deadline, (request time of advent+delay) arrange from short to long, the shortest business of time was in the top of formation.Step S2, pending to as if the business of UGS, rtS, three formations of nrtS, destination node distinguishing from three formations the data of selection scheduling.Step S3, the dispatching algorithm of employing differentiated service grade uses different scheduling strategies to dispatch according to UGS, rtS, nrtS priority order from high to low to it.Step S4, destination node is according to user's under connecting channel quality status, for the user confirms the suitable modulating coded system.Step S5 associates connecting with its affiliated user, distributes the statistics of bandwidth to add up based on the user.Step S6 generates MSH-DSCH_GRANT with the schedule level one result and replies to source node.Generation MSH-DSCH_CONFIRM replied to destination node after step S7, source node received MSH-DSCH_GRANT.Step S8, source node calculates available bandwidth bw_size according to the MSH-DSCH_GRANT that receives, and equity miscellaneous service to be sent carries out allocated bandwidth.The data of dispatching out are generated MACPDU (Protocal Data Uint), be mapped to physical layer.Particularly, the detailed realization of the method for present embodiment can be repeated no more with reference to said method here.
What should explain at last is; Above embodiment is only in order to describe technical scheme of the present invention rather than the present technique method is limited; The present invention can extend to other modification, variation, application and embodiment on using, and therefore thinks that all such modifications, variation, application, embodiment are in spirit of the present invention and teachings.