CN105491674A

CN105491674A - Slot selection optimizing method and device

Info

Publication number: CN105491674A
Application number: CN201410478832.4A
Authority: CN
Inventors: 郭宣羽; 周海军; 冯媛; 房家奕; 唐纪晔
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2014-09-18
Filing date: 2014-09-18
Publication date: 2016-04-13
Anticipated expiration: 2034-09-18
Also published as: CN105491674B

Abstract

The invention relates to the field of communication, and discloses a slot selection optimizing method and device which can be used to solve the problem that slot collision occurs during slot selection. The method includes that: a first node selects a sending slot of itself according to FIs sent by other nodes, wherein each FI carries slot state information of M slots which is reported by one corresponding node, and each piece of slot state information includes occupied node information or measurement information of one slot; the first node selects the slot state information of the M slots according to the latest slot state information to generate the FI, and sends the FI when the next sending slot reaches, in this way, the first node can determine the slots which are not occupied and have the maximum collision likelihood according to information interaction between the first node and the other nodes, and can avoid these slots during sending slot selection, so that the collision likelihood of the sending slots can be reduced, resource cost of information interaction can be reduced, and the operation load of a system can be decreased.

Description

A kind of optimization method of Slot selection and device

Technical field

The present invention relates to the communications field, particularly a kind of optimization method of Slot selection and device.

Background technology

Along with the development of Vehicular communication system and the ripe gradually of mobile self-networking technology, in order to meet the requirement of the real-time of vehicular ad hoc network, reliability, distributed nature, portable is in different bottom communication platforms, inter-vehicle communication agreement based on reliable Reservation ALOHA (ReliableReservedALOHA, RR-ALOHA) is arisen at the historic moment.

RR-ALOHA agreement is the multiplexing access (TimeDivisionMultipleAccess of dynamic Time Division based on structure of time slot, TDMA) channel access protocols, not only there is higher reliability and real-time, the broadcast capability within the scope of single-hop in many cars collaboration communication can be supported, and this agreement can design independent of on physical layer, therefore can in the RR-ALOHA agreement of upper Media access control (MediaAccessControl, the MAC) employing of communication system based on reserving time slots.

Reliable Reservation ALOHA algorithm is a kind of access based on TDMA and resource allocation mechanism, Resourse Distribute based on frame structure in units of slot.In RR-ALOHA mechanism, each node must obtain a primary channel (BasicChannels, BC).After node obtains a BC channel, by periodically transmission frame information (FrameInformation, FI) on the time slot that BC channel is corresponding, every N number of slot forms a frame (being designated as Frame), slot in each frame is numbered 0 ~ N-1, moves in circles between frames.Only allowing a node to send in each slot, is namely TDMA pattern between node.After node takies a time slot, to periodically send the frame information (FrameInformation of fix information institutional framework, FI), the Time Slot Occupancy state that this node directly perceives is carried in FI, namely this node one jumps (Onehop, OH) node in scope is to the service condition of the time slot in former frame, and each node can indicate the seizure condition of each slot in a frame in FI.The FI that each node sends by monitoring its surroundings nodes, obtain the Time Slot Occupancy state (i.e. Time slot allocation situation) with each node of this node within the scope of double bounce, and to upgrade in time Time Slot Occupancy state according to the FI of neighbors and the channel usage of oneself, and by upgrade after Time Slot Occupancy state embody in the FI information oneself sent, thus realize coverage disjoint one jumping bunch between time interval resource reuse.

In data transmission procedure, if terminal does not initiatively abandon time interval resource corresponding to BC, then can use the slot transmission data taken, other nodes can not use this time slot in the meantime always.When the bandwidth that BC channel provides can not meet the requirement of business, the mode by preengaging additional channel takies other idle channels and transmits.For point-to-point communication, node can also be transmitted by reservation point-to-point (P2P) channel, with realize adjacent one to jump bunch in timeslot multiplex, improve the utilance of channel.When message needs to broadcast at whole network, RR-ALOHA mechanism can only select limited terminal to carry out relaying, avoids the network congestion that Flood routing causes.

FI is a vector be made up of N number of time slot state information, and also known as FI information, wherein, N is the timeslot number comprised in a frame.Specifically comprise: Time Slot Occupancy state subdomain, node temporary mark (SourceTemporaryIdentifier, STI) subdomain, priority subdomain and point-to-point service (PTP) indicate subdomain.

Whether, in any one time slot, Time Slot Occupancy state subdomain carries the Time Slot Occupancy state information of this any one time slot, indicate this any one time slot occupied.

In any one time slot, in STI subdomain, carry the STI of the node taking this any one time slot.

In any one time slot, in priority subdomain, carry the priority state that data that the node that takies this any one time slot sends at this any one time slot are corresponding.

In any one time slot, point-to-point service mark subdomain carries the node traffic mark of this any one time slot;

Wherein, the size of time slot state information is 1bit (bit), the size of STI is 8bit, take the size of priority state corresponding to data that the node of time slot sends at this time slot be the size of 2bit, PTP mark is 1bit.

In each frame, node all must send FI by the sending time slots of this node (i.e. this node take time slot), and according to the FI of neighbors obtained and the Time Slot Occupancy state vector (table) of channel usage (i.e. the Time Slot Occupancy state of this node) immediate updating this locality of this node, and embody in the FI that the Time Slot Occupancy state after renewal is sent at this node.

All nodes in each OH bunch bunch in enjoy full-mesh (any node namely in each OH bunch can know the Time Slot Occupancy state of all nodes in this OH bunch).Can not direct communication (node namely in each OH bunch if this node does not belong to the common subset with another bunch, then cannot know the Time Slot Occupancy state of the node of another bunch) if the node belonging to different bunches does not belong to all bunches of common subset.In RR-ALOHA algorithm, when new node adds network, a time slot must be obtained, namely need to perform channel occupancy flow process, take a time slot, after this new node successfully takies a time slot, also need to perform channel maintenance process to this time slot.

The channel occupancy flow process that node performs is illustrated below in conjunction with Fig. 1 and Fig. 2.

Suppose that node first application takies a slot (time slot), its flow chart is shown in Figure 1:

Step 101: first node monitors the channel occupancy situation of a frame before selecting time interval resource.

In the frame of node after starting access procedure, all slot in this frame of monitoring.

During slot in this frame of nodes listen, node receive OH bunch in the FI that sends of other nodes.If the Time Slot Occupancy state of the slotX that the FI instruction that in OH bunch, any one other node sends is corresponding is busy, then the slotX correspondence markings in the time slot state vector (table) of this locality is RESERVED (taking) by node, otherwise is labeled as AVAILABLE (available).

The all FI information received in this frame are carried out dissection process by node respectively, and judge the Time Slot Occupancy state of each slot according to aforesaid way.

Step 102: node, from the time slot in the frame monitored, selects a free timeslot (i.e. availableslot).

When the Time Slot Occupancy state of the middle record of the time slot state vector (table) of some slot in node this locality is AVAILABLE, then think that this slot is idle slot (i.e. free timeslot).

Due to one or more idle slot may be had in a frame of nodes listen, idle slot may be there is no yet, therefore, if there is multiple idle slot in a frame of nodes listen, then therefrom Stochastic choice idle slot, if there is no idle slot in a frame of nodes listen, so regard the time slot that the node lower than self current priority takies as idle slot and select.After selecting idle slot, perform step 103; If the idle slot of neither one for access, then can return step 101, continue to monitor next frame.

Step 103: node judges whether to arrive idle slot selected in step 102.

To suppose in step 102 that selected idle slot is slotp, then, before slotp arrives, continue to monitor each slot, not clear and definite whether before slotp arrives in basic RR-RLOHA algorithm, continue to do the whether still idle judgement of slotp.Arrive slotp, perform step 104.

Step 104: node sends FI at slotp.

Each field (territory) in FI is filled according to following rule;

For in the field corresponding with the sending time slots of this node in FI, the Time Slot Occupancy state of filling in is BUSY (can fill in 1 in the Time Slot Occupancy state subdomain of correspondence), and in STI subdomain, fill in the STI of this node, in priority subdomain, fill in the precedence information of the data that this node sends at sending time slots, fill in PTP mark at point-to-point service mark subdomain;

For the field that other slot except the sending time slots of this node are corresponding, if successfully receive at a certain slot and resolved the FI that a certain node sends, be then BUSY (can to filling in 1 in the Time Slot Occupancy state subdomain of slot) by the Time Slot Occupancy status indication of this slot, and in the STI subdomain of this slot, fill in the STI of corresponding node, in the priority subdomain of this slot, fill in the precedence information that this node sends data, fill in PTP mark at point-to-point service mark subdomain;

If do not receive FI at a certain slot, or cannot resolve after a certain slot receives FI (such as have received the FI sent by multiple node at a certain slot), then this slot is labeled as FREE (can to filling in 0 in the Time Slot Occupancy state subdomain of slot).

Node, after fill in each field in complete FI according to above-mentioned rule, sends this FI at time slot p.

Whether successful step 105: monitor feedback, confirm that this application of this node takies time slot.

If this node is after transmission FI, in all FI received, the sending time slots of this node is all taken (namely in all FI received by this node, the Time Slot Occupancy state of the sending time slots of this node is all marked as busy, and the STI of correspondence is identical with this node), then think that this FI sends successfully, otherwise think that this FI sends unsuccessfully.In actual applications, this process can be realized by logical AND operation.

Node monitors a frame from slotp+1, if all indicate slotp to be taken by this node in the FI of all feedbacks in this frame, then this node continues to send FI information at slotp in the next frame; If in the FI of all feedbacks received in the frame from slotp+1, there is at least one FI indicates the Time Slot Occupancy state of slotp to be FREE, or/and, there is at least one FI indicates the Time Slot Occupancy state of slotp to be BUSY (doing) and STI corresponding to slotp is different from this node, then think that this node sends FI failure at slotp, namely think that the application of this node takies the time slot failure of slotp, return step 102.

The process that node carries out channel maintenance (namely safeguarding the time slot that this node takies) is as follows:

In basic RR-ALOHA, send FI the time slot periodicity that node takies at this node, alternately the Time Slot Occupancy situation of channel is safeguarded by internodal FI.If node does not initiatively abandon the time slot that this section point takies, then the time slot that can always use this node to take carries out transfer of data.If but network configuration changes, node then needs to continue to detect according to the feedback FI received at receiving slot the time slot whether time slot that this node takies take with other nodes and there occurs collision.If the time slot that multiple node takies there occurs collision, then all nodes taking this time slot all need to discharge this time slot, and again initiate access procedure, reserve channel.

Can find out, channel maintenance process flow is a part for channel access process, and figure below provides the sketch of channel access process, as shown in Figure 3:

Audit window: object is to understand complete channel condition information, just can select time interval resource after this window terminates.Audit window length is 1 frame.

Feedback window: just start monitoring after sending FI, according to the information received in feedback window carry out node access maintenance channel whether successfully judge, node is when the information determining that on all receiving slots, (namely in feedback window) receives all gives node positive feedback, node just thinks that the application of this time slot is successful, and node starts to take this time slot.If comprise this sending time slots, feedback window length is 1 frame, if do not comprise this sending time slots, feedback window length is (N-1) individual time slot, and N is total number of time slot in a frame.

Node often receives a FI in receiving slot all to be needed to upgrade time slot state vector (table).

Still for idle slot selected in step 102 for slotp, if the FI that node receives indicates slotp to be taken by this node, namely in the FI received, the time slot state information of corresponding slotp is BUSY (being 1 in Time Slot Occupancy state subdomain), and the STI in STI subdomain is identical with the STI of this node, then what judge that this node receives is positive feedback.

Indicate slotp idle or/and instruction slotp is taken by other nodes if there is at least one FI in the FI that node receives, namely node receives the time slot state information at least one FI is FREE (being 0 in Time Slot Occupancy state subdomain), or/and, the node Time Slot Occupancy state received at least one FI is BUSY, and STI in STI subdomain is different from the STI of this node, then what judge that this node receives is negative feedback.

Under RR-ALOHA mechanism, the time slot that node takies collides and there are following two kinds of situations:

1) time slot that node self takies collides

There is one or more frame information indicates this time slot to be taken by other nodes different from the STI of this node, or there is one or more frame information and indicate this time slot unoccupied (Time Slot Occupancy state is FREE), then determine that this time slot collides.

2) time slot that not a node self takies collides

For the time slot that arbitrary not a node takies self, occur that two and above frame information indicate this time slot to be taken by two and above node (that is: STI is different), then determined that this time slot collides.

Collide if nodal test goes out a certain time slot, then the sending time slots at this node is sent to the node taking this time slot the FI comprising feedback information, indicate this time slot to collide, negative feedback is carried out to the node taking this time slot; Do not collide if nodal test goes out a certain time slot, then the sending time slots at this node is sent to the node taking this time slot the FI comprising feedback information, indicate this time slot not collide, positive feedback is carried out to the node taking this time slot.

Illustrate that node performs the process of channel occupancy and channel maintenance below in conjunction with Fig. 2.In Fig. 2, suppose in each frame, to comprise 6 slot, node is access procedure from slot2, thereafter continue in a frame to monitor, select slot4 as the sending time slots of this node according to starting snoop results in the frame after accessing, then monitoring 2 slot are continued, the FI sending this node is started when arriving slot4, (namely at slot5 in N-1 field (territory) after the FI sending this node, slot0, in slot2 and slot3) obtain the feedback information of other node for the time slot of this node maintenance, decision node is at slot5, slot0, whether other nodes obtained in slot2 and slot3 are positive feedback for the feedback information of the time slot of this node maintenance: if, then continue to obtain the feedback information of other nodes for the time slot of this node maintenance in frame afterwards, and determine whether positive feedback, otherwise, return this operation of sending time slots selecting idle slot as this node.

Due to when using basic RR-ALOHA algorithm to carry out internodal communication, periodically send FI between node, FI information mutual between node is MAC layer information, only carries out alternately for time slot state information, precedence information, STI information and PTP information.For do not have occupied time slot also collision may, can only by receive feedback determine Slot selection whether correct, occur with or without time slot collision.As can be seen here, basic RR-ALOUHA algorithm is unfavorable for reducing the possibility selecting time slot collision, Slot selection inefficiency, is unfavorable for reducing mutual information overhead.

Summary of the invention

The embodiment of the present invention provides a kind of optimization method and device of Slot selection, in order to reduce the possibility that Slot selection collides.

The concrete technical scheme that the embodiment of the present invention provides is as follows:

An optimization method for Slot selection in car networked system, comprising:

First node monitors the frame information FI that other nodes send, and the sending time slots of self is selected according to snoop results, wherein, carry the time slot state information of M the time slot that respective nodes reports in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information;

First node continues the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record;

The time slot state information that first node chooses M time slot according to the time slot state information of each time slot generates FI, and sends when arriving next sending time slots.

Like this, first node can according to the information interaction with other nodes, determine occupied and that collision possibility is maximum time slot, thus these time slots are avoided when choosing sending time slots, and then reduce the possibility of sending time slots appearance collision, improve accuracy and the efficiency of selection of sending time slots selection, simultaneously, be conducive to the resource overhead reducing information interaction, reduce the operating load of system.

Optionally, first node monitors the FI that other nodes send, and selectes the sending time slots of self according to snoop results:

Filter out time slot to be selected according to the FI that other nodes send, wherein, to determine in the FI that other nodes send not exist in for the time slot state information of at least one time slot record take nodal information time, using at least one time slot described as time slot to be selected;

When to determine in the FI that other nodes send for the metrical information of at least one time slot record to be selected all lower than pre-determined threshold, by least one time slot to be selected described alternatively sending time slots;

Choose candidate's sending time slots as sending time slots.

Optionally, choose candidate's sending time slots as sending time slots, comprising:

If only there is candidate's sending time slots, then direct described candidate's sending time slots is chosen to be final sending time slots;

If there are at least two candidate's sending time slots, then select candidate's sending time slots at random as final sending time slots, or, determine the maximum reception gross power of each candidate's sending time slots respectively, and the minimum candidate's sending time slots of the value of selected maximum reception gross power is as final sending time slots, wherein, the maximum reception gross power of candidate's sending time slots refers to reception gross power maximum for the value in each reception gross power of described candidate's sending time slots record in the FI that other nodes report.

Optionally, first node continues the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record, comprising:

Described first node often receives the FI of other nodes transmission at a time slot, then according to the FI received, the FI that described one other nodes that the last time receives send is upgraded, in described FI, carry the time slot state information of M the time slot that described one other nodes report.

First node continues the FI monitoring the transmission of other nodes, and upgrade according to state information when each time slot to local record of the FI of up-to-date reception, and judge whether sending time slots that corresponding described first node is selected does not record and take nodal information and the metrical information of record is all less than pre-determined threshold, if, then maintain selected sending time slots, otherwise, again choose sending time slots.

Optionally, first node, according to the time slot state information of each time slot of up-to-date preservation, judges whether sending time slots that corresponding described first node is selected does not record and takies nodal information and the metrical information of record is all less than pre-determined threshold, comprising:

After first node selectes sending time slots, upper once arrive described sending time slots before, all FI sent according to other nodes of up-to-date reception are unified to be judged;

Or,

After first node selectes sending time slots, upper once arrive described sending time slots before, often receive the FI that other node sends, just judge once.

Optionally, the time slot state information that first node chooses M time slot according to the time slot state information of each time slot generates FI, comprising:

First node chooses the time slot state information of sending time slots;

If in the FI that other nodes send a corresponding time slot record to take nodal information identical, then first node chooses the time slot state information of a described time slot;

If in the FI that other nodes send a corresponding time slot record to take nodal information not identical, then first node determines the nodal information taking this time slot that listens at a described time slot, or, first node determines the metrical information measuring this time slot at a described time slot, and the reception gross power recorded in this metrical information is when being greater than setting threshold, choose described time slot state information;

If a corresponding time slot does not record and takies nodal information in the FI that other nodes send, then first node determines the metrical information measuring this time slot at a described time slot, and the reception gross power recorded in described metrical information is when being greater than setting threshold, choose described time slot state information;

First node filters out the time slot state information of M time slot and generates FI from the time slot state information chosen.

Which decrease the possibility that collision appears in sending time slots, improve accuracy and the efficiency of selection of sending time slots selection, meanwhile, be conducive to the resource overhead reducing information interaction, reduce the operating load of system.

Optionally, first node filters out the time slot state information of M time slot from the time slot state information chosen, and comprising:

First node filters out Q the time slot state information recording and take nodal information from the time slot state information chosen;

First node filters out to record and receives measuring state information from the time slot state information chosen, and M-Q the time slot state information that the SINR recorded in described reception measuring state information is minimum;

Wherein, if first node does not choose the time slot state information of enough M time slot, then supplement the time slot state information of selected part time slot at random.

Optionally, first node, according to the time slot state information of the M a chosen time slot, generates FI, comprising:

Corresponding information field in FI is filled respectively according to the time slot state information of M the time slot chosen, wherein, respectively for each time slot in a described M time slot, adopt X bit record timeslot number, adopt the instruction of Y bit record channel, and adopt Z bit record to take nodal information or metrical information, wherein, X, Y, Z are parameter preset;

Or,

Corresponding information field in FI is filled respectively according to the time slot state information of M the time slot chosen, wherein, what adopt the N number of time slot of N number of bit record chooses result, N is the number of time slot and N>M that comprise in a frame, the channel instruction of M the time slot adopting M bit record to choose, and for each time slot in a described M time slot, adopt W bit record to take nodal information or metrical information respectively, wherein, W is parameter preset.

Reduce further the possibility that collision appears in sending time slots like this, thus avoid when selecting time slot the time slot that easily collides.

Optionally, comprise further:

After first node sends FI, continue the FI receiving the transmission of other nodes;

First node judges in the FI that other nodes send, and what comprise in the time slot state information of the sending time slots record selected for first node effectively takies nodal information, whether is the STI of first node, if, then confirm to access successfully, otherwise, again choose sending time slots.

Like this, the correctness of Slot selection can be confirmed further, ensure to access successfully.

An optimization device for Slot selection, comprising:

Selected cell, for monitoring the FI that other nodes send, and the sending time slots of self is selected according to snoop results, wherein, carry the time slot state information of M the time slot that respective nodes reports in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information;

Updating block, for continuing the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record;

Processing unit, generates FI for the time slot state information choosing M time slot according to the time slot state information of each time slot, and sends when arriving next sending time slots.

Like this can according to the information interaction with other nodes, determine occupied and that collision possibility is maximum time slot, thus these time slots are avoided when choosing sending time slots, and then reduce the possibility of sending time slots appearance collision, improve accuracy and the efficiency of selection of sending time slots selection, meanwhile, be conducive to the resource overhead reducing information interaction, reduce the operating load of system.

Optionally, monitor the FI that other nodes send, and when selecting the sending time slots of self according to snoop results, described selected cell specifically for:

Choose candidate's sending time slots as sending time slots.

Optionally, when choosing candidate's sending time slots as sending time slots, described selected cell specifically for:

Optionally, continue to monitor the FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, described updating block specifically for:

Often receive the FI of other nodes transmission at a time slot, then according to the FI received, the FI that described one other nodes that the last time receives send is upgraded, in described FI, carry the time slot state information of M the time slot that described one other nodes report.

Continue the FI monitoring the transmission of other nodes, and upgrade according to state information when each time slot to local record of the FI of up-to-date reception, and judge whether corresponding selected sending time slots does not record and take nodal information and the metrical information of record is all less than pre-determined threshold, if, then maintain selected sending time slots, otherwise, again choose sending time slots.

Optionally, according to the time slot state information of each time slot of up-to-date preservation, judge corresponding selected sending time slots whether do not record take nodal information and the metrical information of record is all less than pre-determined threshold time, described updating block specifically for:

After selected sending time slots, upper once arrive described sending time slots before, according to the unified judgement of all FI that other nodes of up-to-date reception send;

Or,

After selected sending time slots, upper once arrive described sending time slots before, often receive the FI that other node sends, just judge once.

Optionally, according to the time slot state information of each time slot choose M time slot time slot state information generate FI time, described processing unit specifically for:

Choose the time slot state information of sending time slots;

If in the FI that other nodes send a corresponding time slot record to take nodal information identical, then choose the time slot state information of a described time slot;

If in the FI that other nodes send a corresponding time slot record to take nodal information not identical, then determine the nodal information taking this time slot listened at a described time slot, or, determine the metrical information measuring this time slot at a described time slot, and the reception gross power recorded in this metrical information is when being greater than setting threshold, choose described time slot state information;

If a corresponding time slot does not record and takies nodal information in the FI that other nodes send, then determine the metrical information measuring this time slot at a described time slot, and when the reception gross power recorded in described metrical information is greater than setting threshold, choose described time slot state information;

From the time slot state information chosen, filter out the time slot state information of M time slot and generate FI.

Optionally, when filtering out the time slot state information of M time slot from the time slot state information chosen, described processing unit specifically for:

Q the time slot state information recording and take nodal information is filtered out from the time slot state information chosen;

Filter out from the time slot state information chosen and record metrical information, and M-Q the time slot state information that the SINR recorded in described metrical information is minimum;

Wherein, if do not choose the time slot state information of enough M time slot, then supplement the time slot state information of selected part time slot at random.

Optionally, according to the time slot state information of M the time slot chosen, generate FI time, described processing unit specifically for:

Or,

Optionally, described selected cell is further used for:

After sending FI, continue the FI receiving the transmission of other nodes;

Judge in the FI that other nodes send, what comprise in the time slot state information for selected sending time slots record effectively takies nodal information, whether is the STI of this device, if so, then confirms to access successfully, otherwise, again choose sending time slots.

An optimization device for Slot selection, comprising:

Processor, for reading the program in memory, performs following process:

The FI of other nodes transmission is monitored by transceiver, and the sending time slots of self is selected according to snoop results, wherein, the time slot state information of M the time slot that respective nodes reports is carried in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information, and continue by transceiver the FI monitoring the transmission of other nodes, and carry out real-time update according to the time slot state information of snoop results to each time slot of local record, and the time slot state information generation FI of M time slot is chosen according to the time slot state information of each time slot, and sent by transceiver when arriving next sending time slots,

Transceiver, for receiving under the control of a processor and sending data.

Optionally, monitor by transceiver the FI that other nodes send, and when selecting the sending time slots of self according to snoop results, described processor specifically for:

Choose candidate's sending time slots as sending time slots.

Optionally, when choosing candidate's sending time slots as sending time slots, described processor specifically for:

Optionally, continue to monitor by transceiver the FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, described processor specifically for:

The FI monitoring the transmission of other nodes is continued by transceiver, and upgrade according to state information when each time slot to local record of the FI of up-to-date reception, and judge whether corresponding selected sending time slots does not record and take nodal information and the metrical information of record is all less than pre-determined threshold, if, then maintain selected sending time slots, otherwise, again choose sending time slots.

Optionally, according to the time slot state information of each time slot of up-to-date preservation, judge corresponding selected sending time slots whether do not record take nodal information and the metrical information of record is all less than pre-determined threshold time, described processor specifically for:

Or,

Optionally, according to the time slot state information of each time slot choose M time slot time slot state information generate FI time, described processor specifically for:

Choose the time slot state information of sending time slots;

Optionally, when filtering out the time slot state information of M time slot from the time slot state information chosen, described processor specifically for:

Optionally, according to the time slot state information of M the time slot chosen, generate FI time, described processor specifically for:

Or,

Optionally, processor is further used for:

After sending FI by transceiver, continue by transceiver the FI receiving the transmission of other nodes;

Accompanying drawing explanation

Fig. 1 is prior art lower node application sending time slots flow chart;

Fig. 2 is that prior art lower node performs Time Slot Occupancy process schematic;

Fig. 3 is that prior art lower node performs channel maintenance process schematic;

Fig. 4, Fig. 5 and Fig. 6 are the first FI form schematic diagram that in the embodiment of the present invention, first node adopts;

Fig. 7 is the second FI form schematic diagram that in the embodiment of the present invention, first node adopts;

Fig. 8 is that in the embodiment of the present invention, first node performs Slot selection Optimizing Flow figure;

Fig. 9 and Figure 10 is first node structural representation in the embodiment of the present invention.

Embodiment

In order to reduce the possibility that Slot selection collides, in the embodiment of the present invention, redesign the form of FI, and between each node when mutual FI, the only time slot state information of mutual occupied time slot and the time slot state information of time slot that most possibly collides, wherein, whether time slot occupied is determine according to the nodal information that takies recorded in time slot state information, and time slot whether likely collide be that metrical information according to recording in time slot state information is determined.

Be introduced for car networking in the embodiment of the present application, between node when carrying out FI and being mutual, the FI form adopted has two kinds, is respectively:

The first form for: consult shown in Fig. 4, Fig. 5 and Fig. 6, FI transmits the content of fixing M time slot, the bit number that then in FI, timeslot number takies is X*M bit, FI total length is (X+Y+Z) * M-bit, in the FI that each node sends, the time slot state information of fixing instruction M (0<M<N, the determined value for arranging) individual time slot, each time slot is made up of (X+Y+Z) bit.Wherein, the information of what X bit was used to indicate transmission is which time slot, i.e. timeslot number; Whether Y bit, for recording channel instruction, namely indicates decoding correct, and channel instruction is with { 0,1} represents, wherein 0 represents decoding error, and 1 represents that decoding is correct; Z bit is used for recording data information (D), if decoding is correct, then D carries the jumping user ID demodulated from corresponding time slot, namely the STI of the node of this time slot is taken, if decoding error, then D carries the demodulation signal to noise ratio (SINR) of R bit and the reception gross power of Z-R bit, and wherein R can be 0, R value needs emulation to determine, wherein the concrete length of each time slot is changeless, but the content of time slot carrying needs to be indicated by channel to decide, X, Y, Z are parameter preset.

The second form for: consult shown in Fig. 7, FI frame structure adopts bitmap bitmap format to represent N number of time slot, FI total length is (N+M+W*M) bit, wherein, the time slot state information that N bit is used to indicate which M time slot in N number of time slot that a frame comprises is carried in FI, 1 for carrying, 0 for not carry, it is occupied that M-bit is used to indicate which time slot in M time slot, 1 is occupied, 0 is unoccupied, i.e. channel instruction, W*M bit is used to indicate the time slot state of M time slot, each time slot provides the node STI of Wbit when decoding is correct, the demodulation SINR of R bit and the reception gross power of W-R bit is provided when decoding error, wherein W is parameter preset.

Such as, unified setting X=7, Y=1, Z=8, W=8 in the present embodiment.

Therefore, when M>N/7 (supposing that N is 100), the configuration of FI adopts the second form expense relatively little, time (i.e. M>14.2); And time M<N/7 (i.e. M<14.2), the configuration of FI adopts the first form expense relatively little.

Based on above-mentioned FI structural representation, in the embodiment of the present invention, each node, after mutual FI, also will record time slot state cache table further, specifically as shown in table 1:

Table 1

Record node in time slot state cache table and receive the FI that each node around sends, and when each time slot receives new FI, upgrade the content of time slot state cache table corresponding line.Wherein, can the FI of correct demodulation, then record in this FI the situation that takies of all time slots represented, disturbed condition or metrical information; Can not the FI of correct demodulation, then reception gross power and the SINR of the current time slots measured with node oneself are updated in corresponding time slot.

If FI adopts the first form, first node is when demodulation FI, M time slot is resolved successively according to the size of timeslot number 0 ~ N-1, for the channel domain that any time slot is corresponding, first first node resolves X bit time slots number, then the channel instruction of Y bit is resolved, " 1 " represents that this time slot is occupied, " 0 " represents that this time slot is unoccupied, but collision probability is very large, finally, time slot state is resolved according to channel instruction, if channel is designated as " 1 ", the Z bit then representing below carries the STI of the node taking this time slot, if channel is designated as " 0 ", then represent that Z bit below carries the SINR of this time slot reporting node measurement to arrive and receives gross power,

If adopt the second form at FI, first node is when demodulation FI, the bitmap of N bit before first resolving, what indicate time slot 0 ~ N-1 according to the order of sequence reports situation, for certain time slot i, if in the bitmap of N bit the i-th+1 be set to " 1 ", then represent in FI the information carrying this time slot i, if the i-th+1 is set to " 0 ", then represent the information of not carrying this time slot i in FI; Then, first node resolves the bitmap of M-bit, indicates the channel occupancy situation of M the time slot chosen herein, for certain time slot i, if corresponding bits position is set to " 1 " in the bitmap of M-bit, then represent the STI carrying the node taking this time slot i in FI; If corresponding bits position is set to " 0 " in M-bit bitmap, then carries in expression FI and report node to measure the SINR and reception gross power that obtain at time slot i.Specifically can consult shown in Fig. 7.

Every a line in time slot state cache table receives according to each time slot and the content of the FI of demodulation is filled in, for the time slot i of correct demodulation, other information except timeslot number are filled out in the capable corresponding time slot column element of this i, be about to " channel instruction+time slot state " and fill in in the time slot element of correspondence; For the time slot i of correct demodulation, only " channel indicates the SINR of (0)+first node measurement and receives gross power " be filled up in the i-th row i-th column element, other row contents do not upgrade, and namely represent with " N/A ".

As shown in table 1, suppose that node abcd takies time slot 0,1,2,3 respectively, time slot N-1 does not have occupied, and present node e correctly receives and demodulation of the FI content that node acd sends, the FI content demodulation mistake that node b sends.Such as accepting time slot 0, present node e receives M the time slot state information that node a reports, wherein, STIa representative takies the STI of the node a of time slot 0, STIb representative takies the STI of the node b of time slot 1, the SINR that SINRa2 representation node a records at time slot 2, the reception gross power that Pa2 representation node a records at time slot 2, namely unsuccessful demodulation is not had to go out to take the information of the c node of time slot 2, N/A represents that this time slot does not detect any signal, or do not carry the time slot state information of related time-slot in FI, the SINR+ that any information that can not get other time slots when demodulation mistake only has node self to measure current time slots receives gross power (as shown in the time slot of the column of receiving slot 1 place one line identifier).

Below in conjunction with accompanying drawing, the preferred embodiment of the present invention is described in detail.

Consult shown in Fig. 8, in the embodiment of the present application, the Optimizing Flow that car networking is carried out Slot selection is as follows:

Step 800: first node monitors the FI that other nodes send, and the sending time slots of self is selected according to snoop results, wherein, carry the time slot state information of M the time slot that respective nodes reports in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information.

Concrete, first node is when choosing sending time slots, need the monitoring first carrying out frame data, namely receive continuously from the first frame first time slot and judge the FI that other nodes of surrounding send, and record the time slot state information of M the time slot carried in each FI, until N number of time slot in a business transmission cycle terminates.Wherein, although, the time slot state information of M time slot is all carried in each FI, but, M the time slot state information institute of carrying in different FI for time slot possible different, such as: setting M is 3, and node A carries the time slot state information of slot0, slot1, slot2, Node B carries the time slot state information of slot0, slot1, slot4, and node C carries the time slot state information of slot1, slot3, slot4.Each time slot state information can be the node STT taking this time slot, also can be SINR and the reception gross power of this time slot that this Time Slot Occupancy node measurement arrives.

Secondly, first node can go out not by time slot to be selected that other nodes take according to the time slot state information sifting of each time slot of record, wherein, first node to determine in the FI that other nodes send not exist in for the time slot state information of at least one time slot record take nodal information time (e.g., be metrical information, namely SINR+ receives gross power, or, part is metrical information, and part is N/A), at least one time slot above-mentioned is defined as time slot to be selected.Accordingly, if first node is determined to take nodal information (e.g., STI) for existing in the time slot state information of at least one time slot record in the FI that other nodes send, then this type of time slot is not selected to be time slot to be selected.

Again, when first node to be determined in the FI that other nodes send for the metrical information of at least one time slot record to be selected all lower than pre-determined threshold, by least one time slot to be selected above-mentioned alternatively sending time slots.

Such as, suppose that the time slot state information recorded for time slot 1 in the FI that other nodes that first node receives send is metrical information, what namely the corresponding time slot 1 of other all nodes was recorded is all " SINR+ receives gross power ", and the metrical information that all nodes are recorded is all lower than pre-determined threshold, namely the SINR of every other node record is all lower than the SINR thresholding preset, and every other node records reception gross power all lower than the reception gross power thresholding preset, then first node is by time slot 1 alternatively sending time slots.

In like manner, first node can select multiple other time slots alternatively sending time slots being similar to time slot 1.

Finally, first node chooses one as final sending time slots from the candidate's sending time slots filtered out.

Preferably, if only there is candidate's sending time slots, then first node is directly chosen to be final sending time slots, if and there is multiple candidate's sending time slots, then first node selectes candidate's sending time slots at random as final sending time slots, or, also the maximum reception gross power of each candidate's sending time slots can first be determined respectively, and the minimum candidate's sending time slots of the value of selected maximum reception gross power is as final sending time slots, wherein, the maximum reception gross power of candidate's sending time slots refers to reception gross power maximum for the value in each reception gross power of this candidate's sending time slots record in the FI that other nodes report.

Such as, consult shown in table 1, in the embodiment of the present invention, the metrical information that time slot is corresponding comprises SINR+ and receives gross power, so, when choosing candidate's sending time slots, can adopt following operation:

If the reception gross power recorded in the i-th column element that time slot i is corresponding is all less than predetermined power thresholding and the SINR of record is also all less than default SINR thresholding, then illustrate that time slot i may be idle, then assert that time slot i is idle available, and joined in time slot to be selected;

If the reception gross power of row k record is greater than predetermined power thresholding and SINR is less than default SINR thresholding in the i-th column element that time slot i is corresponding, then illustrate that time slot i is the strong jamming time slot taking node of time slot k, namely may there is collision in time slot i, or, taken by other nodes outside double bounce, so, assert that time slot i is unavailable;

If have the reception gross power of row k record to be greater than predetermined power thresholding in the i-th column element that time slot i is corresponding and SINR is less than default SINR thresholding, then decoding error is described, does not so consider this row k element, accordingly, also judge that time slot i is unavailable.

Step 810: first node continues the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record.

Concrete, from the second frame first time slot, the FI that other nodes of surrounding that each time slot that first node continues to monitor subsequent frame successively receives send, and the time slot state information (namely time slot state cache table can carry out upgrading corresponding a line at each time slot, and preserves the time slot state information of the up-to-date N number of time slot received all the time) recorded in local time slot state cache table of preserving is upgraded according to up-to-date FI.The previous time slot of by the time selected sending time slots terminates (as, if selected time slot p, then wait until that time slot p-1 terminates), utilize up-to-date N*N time slot state cache table, check in the newest F I that other nodes send for sending time slots whether do not record take nodal information and record metrical information be all less than pre-determined threshold (namely sending time slots is not taken by other nodes all the time), if so, then maintain selected sending time slots, otherwise, again choose sending time slots.

In practical application, after first node selectes sending time slots, can upper once arrive this sending time slots before, whether can use according to the unified sending time slots judging that self selectes of all FI that other nodes of up-to-date reception send, or, also can after selected sending time slots, upper once arrive this sending time slots before, often receiving the FI that other node sends, just judging once when upgrading time slot state buffer memory letter table whether self selected sending time slots can use.

Step 820: the time slot state information that first node chooses M time slot according to the time slot state information of each time slot generates FI, and sends when arriving next sending time slots.

When choosing M time slot, first node can according to up-to-date preservation time slot state cache table, judge each time slot from the 0th row to N-1 leu, count the alternative time slot sets including M time slot: concrete, first node can perform but be not limited to following operation:

First, first node chooses the time slot state information of sending time slots.

Concrete, the sending time slots chosen belongs to alternative time slot sets by first node, and the number of time slot m of alternative time slot sets record is added 1;

Secondly, if in the FI that sends of other nodes a corresponding time slot record to take nodal information identical, then first node chooses the time slot state information of an above-mentioned time slot.

Such as: record in the i-th row time slot state information that time slot i is corresponding and effectively take nodal information, namely " STI is taken ", and the STI of record is identical, then time slot i belongs to alternative time slot sets by first node, and the number of time slot m of alternative time slot sets record is added 1.

Again, if in the FI that other nodes send a corresponding time slot record to take nodal information not identical, when then first node determines that the time slot state information that listens to for an above-mentioned time slot when an above-mentioned time slot arrives is for taking nodal information, choose this time slot state information, or, first node determines that the time slot state information listened to for an above-mentioned time slot when an above-mentioned time slot arrives is metrical information, and the reception gross power recorded in this metrical information is when being greater than setting threshold, choose this time slot state information.

Such as: record in the i-th row time slot state information that time slot i is corresponding and effectively take nodal information, namely " STI is taken ", and the STI of record is not identical, then illustrate that time slot collision has appearred in time slot i, so, first node is obtained from the time slot state information (referred to as information i, being the time slot state information recorded in the i-th row i-th row) obtained in time slot i measurement;

If what record in information i is take nodal information, then the STI recorded in information i is taken node as time slot i by first node, and is belonged to alternative time slot sets by time slot i, and the number of time slot m of alternative time slot sets record is added 1;

If what record in information i is metrical information (namely SINR+ receives gross power), then first node judges whether the reception gross power wherein recorded is greater than setting threshold, if so, then time slot i is belonged to alternative time slot sets, and the number of time slot m of alternative time slot sets record is added 1; Otherwise, do not choose time slot i.

Again, if a corresponding time slot does not record and takies nodal information in the FI that other nodes send, then first node determines that self is metrical information for the time slot state information that an above-mentioned time slot listens to when an above-mentioned time slot arrives, and the reception gross power recorded in this metrical information is when being greater than setting threshold, choose this time slot state information.

Such as: do not record in the i-th row time slot state information that time slot i is corresponding and effectively take nodal information, only record the metrical information that each other nodes listen arrive, i.e. " SINR+ receives gross power ", this thing happens, illustrate that first node does not correctly demodulate the information received at time slot i, then first node first node is obtained from the time slot state information (referred to as information i, being the time slot state information recorded in the i-th row i-th row) obtained in time slot i measurement;

If the reception gross power recorded in information i is greater than setting threshold, then time slot i is belonged to alternative time slot sets, and the number of time slot m of alternative time slot sets record is added 1;

If the reception gross power recorded in information i is not more than setting threshold, then do not choose time slot i;

Finally, first node filter out from the time slot state information chosen M time slot time slot state information and generate FI,

Such as: first node filters out Q the time slot state information recording and take nodal information from the time slot state information chosen; And filter out to record from the time slot state information chosen and receive measuring state information, and M-Q the time slot state information that the SINR recorded in this reception measuring state information is minimum.

On the other hand, if do not choose the time slot state information of enough M time slot, then first node also can the time slot state information of random selecting partial time slot, does not repeat them here.

After arrival sending time slots, the FI of generation is sent to other nodes of surrounding by first node, and empties and generate FI.Such as, other nodes around FI sends to when selected sending time slots p arrives by first node, and empty the row that in time slot state cache table, time slot p is corresponding.

In the above-described embodiments, preferably, when generating FI, first node can adopt but be not limited to following two kinds of modes:

First kind of way is: fill corresponding information field in FI respectively according to the time slot state information of M the time slot chosen, wherein, respectively for each time slot in M time slot, adopt X bit record timeslot number, adopt the instruction of Y bit record channel, and adopt Z bit record to take nodal information or metrical information, wherein X, Y, Z are parameter preset;

The second way is: adopt bitmap mode, corresponding information field in FI is filled respectively according to the time slot state information of M the time slot chosen, wherein, what adopt the N number of time slot of N number of bit record chooses result, N is the number of time slot and N>M that comprise in a frame, the channel instruction of M the time slot adopting M bit record to choose, and for each time slot in M time slot, adopt W bit record to take nodal information or metrical information respectively, wherein W is parameter preset.

Such as: first node adopts first kind of way to generate FI, then M time slot is inserted in FI according to timeslot number order from small to large by first node successively, arranges X=7, Y=1, Z=8.

If a time slot is occupied, namely to recording " taking STI " by time slot, then by 7 bit time slots of this time slot number, 1 bit channel instruction (1), and the STI of 8 bit stealing nodes inserts in FI successively;

If a time slot is unoccupied, namely to recording " SINR+ receives gross power " by time slot, then by 7 bit time slots of this time slot number, 1 bit channel instruction (0), and R bit SINR and 8-R bit reception gross power are inserted in FI successively;

According to the method described above, successively M time slot state information is filled in FI, specifically consults shown in Fig. 6.

Again such as: W=8 is set, first node adopts the second way to generate FI, then first node is when filling in each information field in FI, what in FI, first adopt N bit bitmap to record in a frame the N number of time slot comprised chooses result, as, if the bit position that time slot is corresponding is " 1 ", represent that this time slot is selected, if bit position corresponding to time slot is " 0 ", represent that this time slot is not selected; Then, first node adopts M-bit bitmap to record the channel instruction of M the time slot chosen, as, if bit position corresponding to time slot is " 1 ", represent that this time slot is taken by node, if bit position corresponding to time slot is " 0 ", represent that this time slot is not taken by node; Finally, then for each time slot in M time slot, 8 bit record STI are adopted respectively, or, the reception gross power of SINR and the 8-R bit of record R bit.Specifically consult shown in Fig. 7.

Further, first node is after transmission FI, can continue the FI receiving the transmission of other nodes, namely monitor feedback, first node judges in the FI that other nodes send, what comprise in the time slot state information of the sending time slots record chosen for first node effectively takies nodal information, whether be the STI of first node, if so, then confirm to access successfully, otherwise, again choose sending time slots.

Such as, first node sends after FI, from time slot p+1 at time slot p, monitor N-1 time slot, generate (N-1) * N time slot state cache table, in the ending (i.e. the beginning of time slot P+N) of time slot p+N-1, judge N-1 element in the row that time slot p is corresponding:

If in the effective value of N-1 element, all have recorded channel instruction (1) and record STI be the STI of first node, then confirm access successfully;

If in the effective value of N-1 element, have recorded at least one channel instruction (1) and record STI not identical with the STI of first node, then again choose sending time slots.

On the other hand, until first node after time slot p sends FI, from time slot p+1, except monitoring feedback, also need at each time slot according to the FI content update time slot state cache table received.And need as described in step 810, each time slot needs the time slot selected according to the FI content check first node receiving surroundings nodes whether to have collision.

As can be seen from above-described embodiment, in the embodiment of the present invention, in order to the FI expense produced when reducing mutual between car networking interior joint, each node only reports the time slot state information of occupied time slot, and interference ratio is more greatly the time slot state information of the time slot that collision probability is high, like this, each node by FI only transmitting portions node channel instruction, STI or metrical information (i.e. SINR and reception gross power), the metrical information of each time slot measured by node self substitutes the metrical information of the corresponding time slot of the node measurement in traffic safety communication requirement distance range, like this, when choosing sending time slots, these time slots node transmission towards periphery FI can be avoided.

Therefore, by the cooperation between node, for some nodes, some time slots have multiple metrical information (comprise self bottom and receive the metrical information measured), and the state of each time slot obtains from the angle measurement of node self, like this, each node just can understand the Time Slot Occupancy situation of the neighbors of around twice or the above communication requirement distance range of twice, as, by receiving the STI of the node in traffic safety communication requirement distance range, the information of the neighbors of twice or the above communication requirement distance range of twice can be known; And for example, by receiving the SINR of the neighbors in traffic safety communication requirement distance range and receiving gross power, know the information of the neighbors of twice or the above communication requirement distance range of twice, like this, when carrying out sending time slots and selecting, have and enough effectively avoid the large time slot of collision probability, thus ensure the accuracy that sending time slots is chosen, avoid signaling and resource overhead that repeatedly gravity treatment causes, and the also corresponding FI of the decreasing information content of carrying, thus decrease the resource overhead of carrying FI, effectively alleviate the operating load of system.

Based on said method embodiment, consult shown in Fig. 9, the embodiment of the present invention have also been devised the device (i.e. D2D terminal) of the time slot optimum choice in a kind of car networked system, comprising:

Selected cell 900, for monitoring the FI that other nodes send, and the sending time slots of self is selected according to snoop results, wherein, carry the time slot state information of M the time slot that respective nodes reports in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information;

Updating block 910, for continuing the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record;

Processing unit 920, generates FI for the time slot state information choosing M time slot according to the time slot state information of each time slot, and sends when arriving next sending time slots.

Optionally, monitor the FI that other nodes send, and when selecting the sending time slots of self according to snoop results, selected cell 900 specifically for:

Filter out time slot to be selected according to the FI that other nodes send, wherein, to determine in the FI that other nodes send not exist in for the time slot state information of at least one time slot record take nodal information time, using at least one time slot as time slot to be selected;

When to determine in the FI that other nodes send for the metrical information of at least one time slot record to be selected all lower than pre-determined threshold, by least one time slot to be selected alternatively sending time slots;

Choose candidate's sending time slots as sending time slots.

Optionally, when choosing candidate's sending time slots as sending time slots, selected cell 900 specifically for:

If only there is candidate's sending time slots, then direct candidate's sending time slots is chosen to be final sending time slots;

If there are at least two candidate's sending time slots, then select candidate's sending time slots at random as final sending time slots, or, determine the maximum reception gross power of each candidate's sending time slots respectively, and the minimum candidate's sending time slots of the value of selected maximum reception gross power is as final sending time slots, wherein, the maximum reception gross power of candidate's sending time slots refers to reception gross power maximum for the value in each reception gross power of candidate's sending time slots record in the FI that other nodes report.

Optionally, continue to monitor the FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, updating block 910 specifically for:

Often receive the FI of other nodes transmission at a time slot, then according to the FI received, the FI that other nodes that the last time receives send is upgraded, in FI, carry the time slot state information of M the time slot that other nodes report.

Optionally, according to the time slot state information of each time slot of up-to-date preservation, judge corresponding selected sending time slots whether do not record take nodal information and the metrical information of record is all less than pre-determined threshold time, updating block 910 specifically for:

After selected sending time slots, upper once arrive sending time slots before, according to the unified judgement of all FI that other nodes of up-to-date reception send;

Or,

After selected sending time slots, upper once arrive sending time slots before, often receive the FI that other node sends, just judge once.

Optionally, first node according to the time slot state information of each time slot choose M time slot time slot state information generate FI time, processing unit 920 specifically for:

Choose the time slot state information of sending time slots;

If in the FI that other nodes send a corresponding time slot record to take nodal information identical, then choose the time slot state information of a time slot;

If in the FI that other nodes send a corresponding time slot record to take nodal information not identical, then determine the nodal information taking this time slot listened at a time slot, or, determine the metrical information measuring this time slot at a time slot, and the reception gross power recorded in this metrical information is when being greater than setting threshold, choose time slot state information;

If a corresponding time slot does not record and takies nodal information in the FI that other nodes send, then determine the metrical information measuring this time slot at a time slot, and when the reception gross power recorded in metrical information is greater than setting threshold, choose time slot state information;

Optionally, when filtering out the time slot state information of M time slot from the time slot state information chosen, processing unit 920 specifically for:

Filter out from the time slot state information chosen and record metrical information, and M-Q the time slot state information that the SINR recorded in metrical information is minimum;

Optionally, according to the time slot state information of M the time slot chosen, generate FI time, processing unit 920 specifically for:

Corresponding information field in FI is filled respectively according to the time slot state information of M the time slot chosen, wherein, respectively for each time slot in M time slot, adopt X bit record timeslot number, adopt the instruction of Y bit record channel, and adopt Z bit record to take nodal information or metrical information, wherein, X, Y, Z are parameter preset;

Or,

Corresponding information field in FI is filled respectively according to the time slot state information of M the time slot chosen, wherein, what adopt the N number of time slot of N number of bit record chooses result, N is the number of time slot and N>M that comprise in a frame, the channel instruction of M the time slot adopting M bit record to choose, and for each time slot in M time slot, adopt W bit record to take nodal information or metrical information respectively, wherein, W is parameter preset.

Optionally, selected cell is further used for:

After sending FI, continue the FI receiving the transmission of other nodes;

Based on above-described embodiment, consult shown in Figure 10, in the embodiment of the present invention, a kind of optimization device (e.g., D2D terminal) of Slot selection comprises processor 1000, transceiver 1010, memory 1020 and user interface 1030, wherein:

Processor 1000, for reading the program in memory 1020, performs following process:

The FI of other nodes transmission is monitored by transceiver 1010, and the sending time slots of self is selected according to snoop results, wherein, the time slot state information of M the time slot that respective nodes reports is carried in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information, and continue by transceiver 1010 FI monitoring the transmission of other nodes, and carry out real-time update according to the time slot state information of snoop results to each time slot of local record, and the time slot state information generation FI of M time slot is chosen according to the time slot state information of each time slot, and sent by transceiver 1010 when arriving next sending time slots,

Transceiver 1010, for receiving under the control of a processor and sending data.

Optionally, monitor by transceiver 1010 FI that other nodes send, and when selecting the sending time slots of self according to snoop results, processor 10000 specifically for:

Choose candidate's sending time slots as sending time slots.

Optionally, when processor 1000 chooses candidate's sending time slots as sending time slots, processor 1000 specifically for:

Optionally, continue to monitor by transceiver 1010 FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, processor 1000 specifically for:

The FI monitoring the transmission of other nodes is continued by transceiver 1010, and upgrade according to state information when each time slot to local record of the FI of up-to-date reception, and judge whether corresponding selected sending time slots does not record and take nodal information and the metrical information of record is all less than pre-determined threshold, if, then maintain selected sending time slots, otherwise, again choose sending time slots.

Optionally, processor 1000 according to the time slot state information of each time slot of up-to-date preservation, judge corresponding selected sending time slots whether do not record take nodal information and the metrical information of record is all less than pre-determined threshold time, processor 1000 specifically for:

Or,

Optionally, processor according to the time slot state information of each time slot choose M time slot time slot state information generate FI time, processor 1000 specifically for:

Choose the time slot state information of sending time slots;

Optionally, when processor 1000 filters out the time slot state information of M time slot from the time slot state information chosen, processor 1000 specifically for:

Optionally, processor 1000 according to the time slot state information of the M a chosen time slot, generate FI time, processor 1000 specifically for:

Or,

Optionally, processor 1000 is further used for:

After sending FI by transceiver 1010, continue by transceiver 1010 FI receiving the transmission of other nodes;

Wherein, in Fig. 10, bus architecture can comprise interconnected bus and the bridge of any amount, and the various electrical chains of the memory that the one or more processor specifically represented by processor 1000 and memory 1020 represent are connected together.Other electrical chains various of such as ancillary equipment, pressurizer and management circuit etc. and so on can also be connected together by bus architecture, and these are all known in the field, therefore, are no longer described further it herein.Bus interface provides interface.Transceiver 1010 can be multiple element, namely comprises transmitter and receiver, is provided for the unit communicated with other devices various over a transmission medium.For different subscriber equipmenies, user interface 1030 can also be can external in connect the interface needing equipment, the equipment of connection includes but not limited to keypad, display, loud speaker, microphone, joystick etc.

Processor 1000 is in charge of bus architecture and common process, and memory 1020 can the data that use when executable operations of storage of processor 1000.

To sum up, in the embodiment of the present invention, first node selectes the sending time slots of self according to the FI monitoring the transmission of other nodes, wherein, the time slot state information of M the time slot that respective nodes reports is carried in each FI, what each time slot state packets of information contained a time slot takies nodal information or metrical information, then, first node continues monitor and carry out real-time update to the time slot state information of each time slot of local record, and the time slot state information generation FI of M time slot is chosen according to up-to-date time slot state information, send when arriving next sending time slots, like this, first node can according to the information interaction with other nodes, determine occupied and that collision possibility is maximum time slot, thus these time slots are avoided when choosing sending time slots, and then reduce the possibility of sending time slots appearance collision, improve accuracy and the efficiency of selection of sending time slots selection, simultaneously, be conducive to the resource overhead reducing information interaction, the operating load of reduction system.

Those skilled in the art should understand, embodiments of the invention can be provided as method, system or computer program.Therefore, the present invention can adopt the form of complete hardware embodiment, completely software implementation or the embodiment in conjunction with software and hardware aspect.And the present invention can adopt in one or more form wherein including the upper computer program implemented of computer-usable storage medium (including but not limited to magnetic disc store, CD-ROM, optical memory etc.) of computer usable program code.

The present invention describes with reference to according to the flow chart of the method for the embodiment of the present invention, equipment (system) and computer program and/or block diagram.Should understand can by the combination of the flow process in each flow process in computer program instructions realization flow figure and/or block diagram and/or square frame and flow chart and/or block diagram and/or square frame.These computer program instructions can being provided to the processor of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing device to produce a machine, making the instruction performed by the processor of computer or other programmable data processing device produce device for realizing the function of specifying in flow chart flow process or multiple flow process and/or block diagram square frame or multiple square frame.

These computer program instructions also can be stored in can in the computer-readable memory that works in a specific way of vectoring computer or other programmable data processing device, the instruction making to be stored in this computer-readable memory produces the manufacture comprising command device, and this command device realizes the function of specifying in flow chart flow process or multiple flow process and/or block diagram square frame or multiple square frame.

These computer program instructions also can be loaded in computer or other programmable data processing device, make on computer or other programmable devices, to perform sequence of operations step to produce computer implemented process, thus the instruction performed on computer or other programmable devices is provided for the step realizing the function of specifying in flow chart flow process or multiple flow process and/or block diagram square frame or multiple square frame.

Although describe the preferred embodiments of the present invention, those skilled in the art once obtain the basic creative concept of cicada, then can make other change and amendment to these embodiments.So claims are intended to be interpreted as comprising preferred embodiment and falling into all changes and the amendment of the scope of the invention.

Obviously, those skilled in the art can carry out various change and modification to the embodiment of the present invention and not depart from the spirit and scope of the embodiment of the present invention.Like this, if these amendments of the embodiment of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims

1. an optimization method for Slot selection, is characterized in that, comprising:

2. the method for claim 1, is characterized in that, first node monitors the FI that other nodes send, and selectes the sending time slots of self according to snoop results, comprising:

Choose candidate's sending time slots as sending time slots.

3. method as claimed in claim 2, is characterized in that, choose candidate's sending time slots as sending time slots, comprising:

4. method as claimed in claim 2 or claim 3, is characterized in that, first node continues the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record, comprising:

5. method as claimed in claim 2 or claim 3, is characterized in that, first node continues the FI monitoring the transmission of other nodes, and carries out real-time update according to the time slot state information of snoop results to each time slot of local record, comprising:

6. method as claimed in claim 5, it is characterized in that, first node, according to the time slot state information of each time slot of up-to-date preservation, judges whether sending time slots that corresponding described first node is selected does not record and takies nodal information and the metrical information of record is all less than pre-determined threshold, comprising:

Or,

7. method as claimed in claim 2 or claim 3, is characterized in that, the time slot state information that first node chooses M time slot according to the time slot state information of each time slot generates FI, comprising:

First node chooses the time slot state information of sending time slots;

8. method as claimed in claim 7, it is characterized in that, first node filters out the time slot state information of M time slot from the time slot state information chosen, and comprising:

First node filters out and records metrical information from the time slot state information chosen, and M-Q the time slot state information that the SINR recorded in described metrical information is minimum;

9. the method as described in any one of claim 1-8, is characterized in that, first node, according to the time slot state information of the M a chosen time slot, generates FI, comprising:

Or,

10. the method as described in any one of claim 1-8, is characterized in that, comprises further:

The optimization device of 11. 1 kinds of Slot selections, is characterized in that, comprising:

12. devices as claimed in claim 11, is characterized in that, monitor the FI that other nodes send, and when selecting the sending time slots of self according to snoop results, described selected cell specifically for:

Choose candidate's sending time slots as sending time slots.

13. devices as claimed in claim 12, is characterized in that, when choosing candidate's sending time slots as sending time slots, described selected cell specifically for:

14. devices as described in claim 12 or 13, is characterized in that, continue to monitor the FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, described updating block specifically for:

15. devices as described in claim 12 or 13, is characterized in that, continue to monitor the FI that other nodes send, and when carrying out real-time update according to the time slot state information of snoop results to each time slot of local record, described updating block specifically for:

16. devices as claimed in claim 15, it is characterized in that, according to the time slot state information of each time slot of up-to-date preservation, judge corresponding selected sending time slots whether do not record take nodal information and the metrical information of record is all less than pre-determined threshold time, described updating block specifically for:

Or,

17. devices as described in claim 12 or 13, is characterized in that, when the time slot state information choosing M time slot according to the time slot state information of each time slot generates FI, described processing unit specifically for:

Choose the time slot state information of sending time slots;

18. devices as claimed in claim 17, is characterized in that, when filtering out the time slot state information of M time slot from the time slot state information chosen, described processing unit specifically for:

19. devices as described in any one of claim 11-18, is characterized in that, according to the time slot state information of M the time slot chosen, when generating FI, described processing unit specifically for:

Or,

20. devices as described in any one of claim 11-18, it is characterized in that, described selected cell is further used for:

After sending FI, continue the FI receiving the transmission of other nodes;