WO2008113243A1

WO2008113243A1 - Method and device for allocating gts time slot

Info

Publication number: WO2008113243A1
Application number: PCT/CN2007/071406
Authority: WO
Inventors: Pei Liu; Pingping Xu; Huamin Chen
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-03-20
Filing date: 2007-12-29
Publication date: 2008-09-25
Also published as: CN101272178B; CN101272178A

Abstract

A method for allocating Guaranteed Time Slot (GTS) time slots is disclosed. According to the method, receive a GTS request from a requesting node; if determine that the remaining time slots used for GTS allocation within a current superframe do not satisfy the requirements of the GTS request (201), allocate the GTS time slots to the requesting node in an allocation way of sharing a GTS (203); otherwise, allocate the GTS time slots to the requesting node in an existing way of GTS allocation (202). Meanwhile, a GTS allocation device is disclosed.

Description

Time slot guarantee mechanism time slot allocation method and device

The present invention relates to a wireless personal area network (WPAN) technology, and in particular to a time slot guarantee mechanism (GTS, Guaranteed Time Slot) time slot allocation method and device. Background of the invention

WPAN is a low-rate, low-power, low-complexity network that includes a large number of wireless nodes. Potential applications include sensors, remote control toys, smart badges, remote controls, and home automation devices. The IEEE, Institution of Electrical and Electronics Engineers (IEEE) has developed a Media Access Control (MAC) layer protocol for the implementation of WPAN. Its transmission range is about 10m in the typical transmission range of WPAN. The standard specifies three optional data rates for WPAN: 250kbit/s, 40kbit/s, and 20kbit/s; two addressing modes: 16-bit and 64-bit addressing; three operating bands: 2.4GHz 16 channels, 10 channels in the 915 MHz band and 1 channel in the 868 MHz band.

The IEEE 802.15.4 standard specifies that WPAN has two modes of operation, one is beacon-enabled mode and the other is ηοη beacon-enabled mode. In the non-beacon enable mode, all nodes in the network compete for the channel through the non-slot carrier sense multi-access/collision avoidance (CSMA/CA, Carrier Sense Multi-Access/Collision Avoidance) algorithm. The advantage of the non-beacon enable mode is its self-organization, but it does not provide time guarantee and quality of service (QoS) guarantee. In the beacon enable mode, the network coordinator periodically sends a superframe to organize communication, and the real-time communication and quality of service can be obtained by using a superframe method to allocate non-contention time slots in a superframe for communication transmission. Satisfy. Compared with the non-beacon enable mode, the beacon enable mode better guarantees real-time transmission quality and quality of service.

FIG. 1 is a schematic diagram of a structure of a conventional superframe. As shown in Figure 1, the transmission interval of two consecutive beacon frames is represented by a beacon interval (BI, Beacon Interval), which is divided into an active period and an inactive period. The active period includes a beacon frame transmission period, a CAP (Contention Access Period), and a non-contention access period (CFP, Contention Free Period). During the inactive period, the node does not send data and goes to sleep to save energy.

The active period of the superframe, also known as the superframe duration (SD), is divided into 16 equal-length slots, as shown in Figure 1 from 0 to 15. The length of each time slot, and the number of time slots included in the CAP, are preset by the network coordinator and broadcast to all nodes in the network through the beacon frame transmission period at the beginning of the superframe.

BI and SD are related to the beacon frame index (BO, Beacon Order) and superframe index (SO, Superframe Order), respectively, and the calculation formulas are as shown in formula (1) and formula (2):

BI = aBaseSuperframeDuration x 2 ^B0 ( 1 )

SD = aBaseSuperframeDuration x 2 ^S0 ( 2 ) where the parameter aBaseSuperframeDuration is the minimum length of the superframe when SO=0, the standard given parameter aBaseSuperframeDuration is 960 symbols (symbols), where lsymbol = 4 bits (bit), conversion After that, it is 15.36ms.

During the CAP period, each node transmits data through the non-slotted CSMA/CA algorithm to compete for the channel. However, if the node that needs to transmit data requires relatively high QoS and does not require timeliness, the channel can be contiguous during the CAP period. , sends an allocation GTS request to the network coordinator, requesting to send data during the CFP period. After successfully obtaining the GTS, the node can get The obtained GTS directly transmits data without using the CSM A/CA algorithm to compete for the channel. The minimum length of the CAP period (aMinCAPLength) is 440symbols, but if GTS is used, the length of the CAP is allowed to be temporarily less than the minimum length value.

The format of the GTS request sent by each node to the network coordinator is shown in Table 1 and Table 2:

Table 1: GTS Requests

As shown in Table 1, the GTS request consists of an MHR domain, a command frame identifier field, and a GTS feature field. The MHR field includes 7 bytes for identifying MAC frame header information. The command frame identifier field includes 1 byte for The request is identified as a GTS request; the GTS feature field includes 1 byte for identifying the feature information of the GTS request.

Table 2: GTS feature fields

As shown in Table 2, the GTS feature field is composed of a GTS length field, a GTS direction field, a feature type field, and a reserved field, where the GTS length field includes 3 bits for identifying when the GTS request is requested to be allocated or released. The GTS direction field includes 1 bit for identifying the GTS direction, for example, uplink or downlink. The feature type field includes 1 bit, which is used to identify the type of the GTS request, that is, whether the GTS request is a GTS allocation request or GTS release request.

After receiving the GTS request sent by the node, the network coordinator checks whether the remaining time slots in the current superframe that can be used for GTS allocation meet the GTS request requirement according to the information carried in the GTS request, that is, whether it is greater than or equal to the GTS length field. The number of time slots required to be allocated, if not satisfied, rejects the GTS request; if so, accepts the GTS request and allocates a GTS requiring the number of allocated time slots. After that, the node that initiated the GTS request passes The beacon frame learns the GTS start and end time allocated by itself, and transmits data during the start and stop time of the GTS.

The standard stipulates that a maximum of 7 GTSs can be allocated in a superframe. Each GTS can consist of several time slots. The GTS allocated for each node needs to ensure that the node can complete data transmission before the end of the GTS. The inventor found in the study that, in general, the number of nodes in the network is more than the maximum number of GTSs that can be allocated. In this case, if the 7 GTSs are already occupied, if there are other nodes because If the GTS needs to be sent and the GTS is requested, the network coordinator will reject the request because there is no remaining GTS, and the data of the node cannot be sent in time, which limits the utilization of the GTS. In addition, since each GTS includes at least one time slot, that is, the minimum granularity of the GTS is one time slot, the nodes that are smaller in the transmission rate cannot fully utilize the applied GTS, thereby causing waste of resources. Summary of the invention

The embodiment of the invention provides a GTS allocation method, which can improve the GTS utilization rate. The embodiment of the invention provides a GTS distribution device, which can improve the GTS utilization rate. The technical solution of the embodiment of the present invention is implemented as follows:

A time slot guarantee mechanism GTS allocation method, the method includes:

Receiving a GTS request from the requesting node, when it is determined that the remaining time slots in the current superframe that can be used for the GTS allocation cannot satisfy the GTS request requirement, the requesting node is allocated a GTS time slot according to the shared GTS allocation mode.

A GTS distribution device, the device comprising:

a first determining module, configured to receive a GTS request from the requesting node, to determine whether the remaining time slots in the current superframe that can be used for GTS allocation meet the GTS request requirement;

a shared GTS allocation module, configured to determine that the result of the first determining module is current When the remaining time slots in the superframe that can be used for GTS allocation cannot satisfy the GTS request requirement, the requesting node is allocated a GTS time slot according to a shared GTS allocation mode.

It can be seen that, by adopting the technical solution of the embodiment of the present invention, after receiving the GTS request sent by the node, the network coordinator adaptively selects an appropriate GTS allocation mode according to the current network condition, thereby realizing efficient and reasonable allocation of network resources. , improved GTS utilization. BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent to those skilled in the <

1 is a schematic diagram of a structure of a conventional superframe;

2 is a general flow chart of an embodiment of a method of the present invention;

3 is a flow chart of one embodiment of a method of the present invention;

4 is a schematic diagram of a node B transmitting data by using an allocated GTS according to an embodiment of the present invention; FIG. 5 is a schematic diagram of a data arrival curve of a node A according to an embodiment of the present invention;

6 is a schematic diagram of a node B sharing a same GTS with a node A according to an embodiment of the present invention; FIG. 7 is a schematic diagram of three nodes sharing the same GTS according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a comparison between the existing GTS allocation mode and the improved GTS utilization mode of the GTS allocation mode of the present invention;

9 is a schematic structural diagram of an embodiment of an apparatus according to the present invention;

FIG. 10 is a schematic structural diagram of a shared GTS allocation module according to an embodiment of the present invention. Mode for carrying out the invention

In the embodiment of the present invention, the GTS request from the requesting node is received, and it is determined whether the remaining time slots in the current superframe that can be used for GTS allocation meet the GTS request requirement. If not, the GTS is allocated to the requesting node according to the shared GTS allocation mode. Time slot, ie allocation request The node shares its assigned GTS with the node that has been currently assigned to the GTS; if so, the requesting node is assigned a GTS slot in accordance with the existing GTS allocation. In a practical application, the specific performer of the foregoing steps in the embodiment of the present invention may be a network coordinator.

The present invention will be further described in detail below with reference to the accompanying drawings.

2 is a general flow chart of an embodiment of a method of the present invention. As shown in Figure 2, the following steps are included:

Step 201: The network coordinator receives the GTS request from the requesting node, and determines whether the remaining time slots in the current superframe that can be used for the GTS allocation meet the GTS request requirement. If yes, step 202 is performed; otherwise, step 203 is performed.

In this step, after receiving the GTS request from the requesting node, the network coordinator determines whether the remaining time slots in the current superframe that can be used for GTS allocation can satisfy the number of time slots allocated in the GTS request. The specific implementation method is completely consistent with the existing method, and will not be described here.

In order to implement the method of the present invention, it is necessary to extend the existing GTS request, and expand the GTS feature field shown in Table 1 from the existing 1 byte to 3 bytes, as shown in Table 3, and Table 3 is the expanded GTS request format:

Table 3: Extended GTS Requests

As can be seen from Table 3, the extended GTS request consists of 11 bytes: the first to seventh bytes are MHR fields; the eighth byte is the command frame identification field; the 9th through 11th bytes are GTS feature fields.

Table 4 shows the format of the GTS feature field in the extended GTS request: Bit:

0 ~ 3 4 5 6 ~ 9 10 - 13 14 - 18 19 20 - 23

GTS length GTS feature burst data to delay allocation reservation direction type length reach rate requirement type

Table 4: Extended GTS feature fields

As shown in Table 4, the extended GTS feature field has an allocation type field, a burst length field, a data arrival rate field, and a delay requirement field compared to the existing GTS feature field. The burst length field, the data arrival rate field, and the delay requirement field are respectively used to identify the burst length, the data arrival rate, and the delay requirement information of the service of the requesting node, and an allocation type field, which is used to identify whether the requesting node is allowed. The network coordinator assigns GTS time slots to it according to the shared GTS allocation mode, which can be set to 1 or 0. If the allocation type field is set to the requesting node to allow the network coordinator to assign a GTS time slot to it according to the shared GTS allocation mode, such as 1, the burst length field, the data arrival rate field, and the delay requirement field respectively set the service of the requesting node. The length of the transmission, the rate of arrival of the data, and the delay requirement information; otherwise, the burst length field, the data arrival rate field, and the delay requirement field are set to null.

It should be noted that the number of bits occupied by each flag bit and their order in the extended GTS feature field can be adjusted according to the actual situation, and does not have to be exactly the same as shown in Table 4, as long as the setting is completed, the node Both the network coordinator and the network coordinator understand the purpose of the settings and know how to perform the corresponding operations according to the settings made.

Step 202: The network coordinator allocates a GTS time slot to the requesting node according to an existing GTS allocation manner.

Step 203: The network coordinator allocates a GTS time slot to the requesting node according to the shared GTS allocation mode.

In this step, the specific process of the network coordinator assigning the GTS time slot to the requesting node according to the shared GTS allocation mode is: The network coordinator selects the shared node from the nodes that have currently allocated the GTS time slot, and the selection method is many, for example, may be randomly selected; or, one of the nodes currently assigned to the GTS is selected in descending order of GTS utilization. Or a plurality of shared nodes, the specific selection manner may be: the network coordinator calculates the GTS utilization rate of each node that has been allocated to the GTS, and determines whether the number of time slots included in the GTS allocated by the node with the lowest GTS utilization rate is satisfied. The GTS request request; if yes, the node is selected as the shared node; if not, the sum of the number of slots allocated by the node with the lowest GTS utilization rate and the node with the lowest GTS utilization rate satisfies the GTS request. If it is still not satisfied, continue to increase the number of nodes until the GTS request request is met. Then, the network coordinator determines whether the requesting node and the selected shared node satisfy the GTS sharing requirement, and if so, the allocation requesting node shares the allocated GTS with the sharing node; otherwise, rejects the GTS request.

The network coordinator determines whether the requesting node and the selected shared node meet the GTS sharing requirement: the network coordinator extracts the burst length, the data arrival rate, and the delay requirement information of the service in the GTS request, according to the burst length of the service. The information obtains the service delay of the node that sends the GTS request and the shared node, and determines whether the service delay of the requesting node and the shared node is less than or equal to the respective delay requirement. If both are less than or equal to, the requesting node and the sharing are further determined. Whether the sum of the data arrival rates of the nodes is smaller than the relative bandwidth of the GTS allocated by the shared node, and if not, determining that the requesting node and the shared node satisfy the GTS sharing requirement.

After allocating the GTS for the node in the shared mode, the network coordinator broadcasts the GTS start and end time shared by the requesting node and the shared node and the manner of sharing the GTS to each node in the beacon frame of the next superframe. In the subsequent process, the requesting node and the sharing node can share and use the allocated GTS to send data. For example, the GTS may be used alternately in each of two adjacent superframes to transmit data; or, three consecutive superframes may be regarded as a group, and GTSs in consecutive two superframes are allocated to the requesting node. The remaining one is assigned to the shared section Point; or, assign the GTS in two consecutive superframes to the shared node, and the remaining one is assigned to the requesting node. In short, the distribution method is not fixed and needs to be determined according to the actual situation.

In this step, before the network coordinator determines whether the requesting node meets the GTS sharing requirement, the network coordinator may further include: determining, by the network coordinator, whether there is a time slot that is not occupied by other nodes, and if yes, assigning the unoccupied time slot The requesting node is then allocated a GTS time slot for the requesting node according to the sharing mode; of course, if there is no time slot resource that is not occupied by other nodes, the network coordinator directly allocates the GTS time slot to the requesting node according to the sharing mode. This step considers that although the remaining time slots of the current super frame cannot satisfy the number of time slots allocated in the GTS request, it does not mean that there are no remaining time slots in the current super frame, for example, the remaining one in the current super frame. Time slot, and the GTS request requires allocation of two time slots, then, for this case, the network coordinator may choose to first allocate the remaining one time slot to the requesting node, and then allocate the required requesting node according to the sharing mode. Another time slot.

In this step, before the network coordinator allocates the GTS time slot to the requesting node according to the shared GTS allocation manner, the network coordinator may further include: the network coordinator determines whether the requesting node is allowed to share according to the sharing.

The GTS allocation mode allocates a GTS time slot for it. The specific judgment method is: The network coordinator reads the allocation type field information in the GTS request, and if the field is set to allow the network coordinator to allocate the GTS time slot according to the shared GTS allocation manner, for example, setting If 1, the network coordinator allocates a GTS slot to the requesting node according to the shared GTS allocation manner; otherwise, the network coordinator rejects the GTS request.

Before the network coordinator determines whether the requesting node and the selected shared node meet the GTS sharing requirement, the network coordinator may further include: determining, by the network coordinator, whether the selected sharing node allows the requesting node to share the GTS to which it is allocated, if not allowed, Reselect the shared node. The judgment mode and the network coordinator determine whether the requesting node is allowed to allocate the same GTS time slot according to the shared GTS allocation manner, and details are not described herein. 3 is a flow chart of an embodiment of a method of the present invention. As shown in Figure 3, the following steps are included:

Step 301: The network coordinator receives the GTS request from the node.

For convenience of description, in this embodiment, the node that sends the GTS request is referred to as Node B. Step 302: The network coordinator determines whether the remaining time slot in the current superframe that can be used for the GTS allocation can meet the GTS request requirement. If yes, go to step 303; otherwise, go to step 304.

The judging method is: The network coordinator judges whether the remaining slots in the current superframe can be used for GTS allocation, that is, whether the number of slots not occupied by the GTSs of other nodes satisfies the number of slots allocated by the GTS request.

Step 303: The network coordinator allocates a GTS time slot to the Node B according to the existing GTS allocation manner, and ends the process.

In this step, the network coordinator allocates a corresponding time slot to the node B according to the GTS request request, and broadcasts the GTS start time allocated to the node B to each node in the network in the beacon frame of the next super frame.

In the subsequent process, Node B can use the allocated GTS to send data. FIG. 4 is a schematic diagram of Node B transmitting data by using the allocated GTS according to an embodiment of the present invention. As shown in Fig. 4, assuming that the 16th time slot is assigned to Node B as a GTS, then in successive N superframes, Node B can use the allocated GTS to transmit data until the data is transmitted. Before Node B sends the data, the GTS is directly assigned to Node B, and other nodes cannot use it to send data.

Step 304: The network coordinator determines whether the node B is allowed to allocate a GTS time slot according to the shared GTS allocation manner. If yes, step 305 is performed; otherwise, step 307 is performed.

The judgment mode is: the network coordinator extracts the allocation type field information in the GTS request sent by the node B, and if the allocation type field is set to 1, it determines that the node B allows the network coordinator The GTS time slot is allocated according to the shared GTS allocation mode; otherwise, it is determined not to be allowed. Step 305: The network coordinator determines whether the node B satisfies the GTS sharing requirement. If yes, step 306 is performed; otherwise, step 307 is performed.

In this step, the network coordinator determines whether the node B satisfies the GTS sharing requirement: the network coordinator extracts the burst length, the data arrival rate, and the delay requirement information of the service in the GTS request; and obtains the burst length information according to the service. The service delay of the Node B and the selected shared node, and determining whether the service delays of the Node B and the shared node are respectively less than or equal to the respective delay requirements; if both are less than or equal to, further determining the Node B and the shared node The sum of the data arrival rates is less than the GTS relative bandwidth allocated by the shared node. If less, the node B is determined to satisfy the GTS sharing requirement.

For example: Suppose the network coordinator has allocated all the time slots in the current superframe that can be used for GTS allocation to several nodes that have sent GTS requests before the node B. Then, if the node B wants to send data, it can only The assigned GTS is shared with other nodes that have assigned GTS slots. The network coordinator first calculates the GTS utilization of each node that has been allocated to the GTS, and selects the node with the lowest GTS utilization as the node to be GTS shared with the node B. The GTS utilization rate of each node is calculated as: Calculate the ratio of the amount of data actually generated by each node in a BI to the amount of data that the GTS can actually transmit. For example, the actual amount of data that GTS can transmit is 10 kbps, and the actual amount of data generated by a node during the GTS time period is only 5 kbps, and the GTS utilization rate of the node is 50%. The amount of data actually generated by the node can be obtained by the data arrival curve (0 = b + /t, where b represents the burst length of the service, r represents the data arrival rate, t represents the time; the amount of data that the GTS can actually transmit The calculations can utilize existing technology.

各 The nodes that have been assigned to the GTS have reported the burst length b, the data arrival rate r, and the delay requirement _{max of} the service when requesting the GTS from the network coordinator; the network coordinator can know from the information. The data of each node reaches the curve, for example, A node, the node A is assumed that the burst length of the traffic reported, b, r and rate of arrival of data latency requirement) _max are 100bits 4kbps and 200ms, then the data of the node A is the arrival curve

= 0.1+ 3⁄4 ), as shown in FIG. 5, FIG. 5 is a schematic diagram of a data arrival curve of the node A in the embodiment of the present invention. According to the data arrival curve, the network coordinator can calculate the amount of data actually generated by the node A in the time corresponding to the GTS, and then obtain the GTS utilization rate of the node A. Corresponding to FIG. 5, the amount of data actually generated by the node A is the integral value of the data arrival curve 501 corresponding to the time line 502. In the same way, the network coordinator can calculate the GTS utilization of other nodes that have been assigned to the GTS. The final calculation result of H殳 shows that the GTS utilization of node A is the lowest, then the network coordinator selects node A to perform GTS sharing with node B.

The network coordinator can also calculate the service delay of node A according to the information reported by node A, as shown in formula (3):

Where C is the channel capacity; Γ _{ώ ί ί ί ί ί ί ί ί ί ί} ) _Α less than 200ms, it can be seen that node A can use the allocated GTS to send data.

After selecting node A, the network coordinator judges whether the node 能够 can share the GTS of the node 根据 according to the node 1 and the node 1 and the information, and assumes that the br and _{max of the} node B are 400 bits 2 kbps and 150 ms, respectively, and the node A The allocated GTS occupies only one time slot, and its relative bandwidth is 10 kbps. Then, according to formula (4), the service delay of node A and node B can be calculated: r _AB =2BI-T _to =60.48ms

= 60.88ms 0 < b _A < CT _{data A} ( 4 ) D _B = ^ ^{+ T} B + - _{iata B} ) = 122.428ms 2CT _{iata B} < b _B < 3CT _{data B} visible, calculated node A and node B The service delay is 60.88ms and 122.428ms, which are less than the respective delay requirements of 200ms and 150ms. Therefore, Node B satisfies the initial requirements for GTS sharing with Node A. The network coordinator further determines whether the sum of the data arrival rates of the node A and the node B is smaller than the relative bandwidth of the GTS allocated by the node A, because the data arrival rates of the node A and the node B in this embodiment are 4 kbps and 2 kbps, respectively. The sum is 6 kbps, which is smaller than the relative bandwidth of the GTS by 10 kbps. Therefore, the Node B can share the GTS allocated by the node A with the node A.

Step 306: The network coordinator allocates a GTS slot to the Node B according to the GTS sharing mode. Corresponding to step 305, the network coordinator allocates the GTS allocated by the node A to the node B. Thereafter, the network coordinator broadcasts the GTS start and end time allocated for Node B to each node through the beacon frame in the next superframe, and specifies how Node B and Node A share the GTS. For example, it may be that two nodes in the adjacent superframe use the GTS to transmit data in turn. In the subsequent process, Node B can share the GTS transmission data with Node A according to the allocated GTS.

FIG. 6 is a schematic diagram of Node B and Node A sharing the same GTS according to an embodiment of the present invention. For convenience of description, only one GTS, that is, the GTS shared by Node B and Node A, is shown in FIG. 6. In different superframes, Node A and Node B alternately use the GTS to transmit data.

Step 307: The network coordinator rejects the GTS request and ends the process.

It should be noted that if the sharing of the GTS with the node A still fails to satisfy the data transmission requirement of the node B, the network coordinator can allocate the node B to simultaneously share the GTS with the two nodes. If the two nodes still do not meet the requirements, the analogy can be pushed to further increase the shared GTS. Judge The manner in which the Node B can share the GTS with other nodes is the same as the method for determining whether the Node B and the Node A can share the GTS as described above, and details are not described herein again.

Moreover, the present invention is not limited to only two nodes sharing the same GTS. According to actual needs, three or more nodes may share the same GTS, but the GTS sharing requirement must be met.

For example, after the network coordinator allocates the GTS for the Node B, it also receives the GTS request from the Node C. Similarly, the network coordinator allocates the GTS slot to the Node C according to the shared mode. Assuming that the GTS with the lowest utilization rate is still the GTS shared by Node A and Node B, the network coordinator will first determine whether Node C can implement GTS sharing with Node A and Node B. Assuming that the nodes (!, r, and ) _max are 800 bits 3 kbps and 500 ms, respectively, the service delays of nodes AB and C can be calculated according to formula (5):

Γ =3BI-T _sto =91.2ms

D _A = + T = 91.6ms < 0 ≤ b _A ≤ CT _{data A} < D _B = ^ + T^, + 2(5/ - T _{iata B} ) = 153.088m, > D _m ^B _ax 2CT _{data B} < b _B < 3CT _{data B} D _c = ^ + T _ABC + 5(5/ - T _{iata C} ) = 245.12m, < D _m ^c _ax 5CT _{data C} < b _c < 6CT _data _ _c

(5) It can be seen from the above equation that the service delay of Node B is greater than its own delay requirement and does not meet the GTS sharing requirement. Therefore, Nodes A B and C cannot share the GTS at the same time.

However, if the original allocated GTS of node A includes two time slots, then in this case, the service delays of nodes AB and C calculated according to formula (6) become correspondingly: Γ^=2ΒΙ-2Τ =59·52«^

D _A = + T = 59.92ms < 0≤b _A ≤ CT _{data A}

3⁄4 =^ + ^+ 2(5/ - T _{iata B} ) = 121.408m, < 2CT _{data B} <b _B < 3CT _{data B} = ^ + ^ABC + 5(BI - T _{iata C} ) = 213.44m, < D _m ^c _ix 5CT _{data C} <b _c <6CT _data _ _c

(6) It can be seen that if the GTS allocated by the node A includes two time slots, the service delays of the nodes A, B, and C can satisfy the requirement, and the sum of the data arrival rates of the three nodes is 9 kbps, which is smaller than the GTS. Relative bandwidth, so in this case, three nodes can share the same GTS. FIG. 7 is a schematic diagram of three nodes sharing the same GTS according to an embodiment of the present invention. As shown in FIG. 7, three nodes may use the allocated GTS in turn.

It can be seen from the previous introduction that after the improved GTS allocation mode of the present invention, the network coordinator can flexibly select, according to the actual situation, which node or nodes that have sent the GTS request have been assigned to the GTS node. GTS shares, and it is flexible to determine that several nodes share the same GTS as long as the sharing requirements are met.

FIG. 8 is a schematic diagram of a comparison between the existing GTS allocation mode and the improved GTS allocation mode of the present invention, that is, the GTS utilization ratio in the shared GTS allocation mode. The data shown in Fig. 8 is obtained under the condition that the duty ratio is equal to 0.5 and SO is equal to zero. The utilization of GTS in this figure is defined as the ratio of data transmission time to GTS duration: Λ=^; When a superframe contains multiple GTSs, the GTS utilization rate is the average of the individual GTS utilizations:

As shown in FIG. 8, the line 801 represents the GTS utilization rate in the existing GTS allocation mode, and the curve 802 represents the GTS utilization rate in the improved GTS allocation mode of the present invention. Obviously, The improved GTS allocation method of the present invention can significantly improve the utilization of GTS.

Based on the above method, FIG. 9 is a schematic structural diagram of an apparatus according to an embodiment of the present invention. As shown in FIG. 9, the device includes at least: a first determining module 901 and a shared GTS allocating module 902. The first determining module 901 is configured to receive a GTS request from the requesting node, and determine that the current superframe can be used for GTS allocation. Whether the remaining time slots satisfy the GTS request requirement;

The shared GTS allocation module 902 is configured to allocate, according to the shared GTS allocation manner, the requesting node, when the judgment result of the first determining module 901 is that the remaining time slots that can be used for GTS allocation in the current super frame cannot meet the GTS request requirement. GTS time slot.

FIG. 10 is a schematic structural diagram of a shared GTS allocation module according to an embodiment of the present invention. As shown in FIG. 10, the shared GTS allocation module 902 specifically includes a selection module 9021, a second determination module 9022, and an allocation module 9023.

The selecting module 9021 is configured to: when the judgment result of the first determining module 901 is that the remaining time slots that can be used for GTS allocation in the current super frame cannot meet the GTS request requirement, the node that has already allocated the GTS time slot from the current Select a shared node that will be GTS shared with the requesting node;

The second determining module 9022 is configured to determine whether the shared node selected by the requesting node and the selecting module 9021 meets the GTS sharing requirement;

The allocating module 9023 is configured to: when the judgment result of the second judging module 9022 is that the requesting node and the sharing node meet the GTS sharing requirement, allocate the GTS of the sharing node to the node that initiates the GTS request according to the sharing manner; otherwise, reject the GTS request.

Alternatively, the shared GTS allocation module 902 specifically includes a third determining module 9024, a selecting module 9021, a second determining module 9022, and an allocating module 9023;

The third judging module 9024 is configured to: when the judgment result of the first judging module 901 is that the remaining time slots that can be used for the GTS allocation in the current super frame cannot satisfy the GTS request request, determine, according to the GTS request, whether the requesting node allows Network Coordinator is allocated according to shared GTS The mode assigns a GTS time slot to it, and if so, notifies the selection module 9021 to select the shared node; otherwise, rejects the GTS request;

The selecting module 9021 is configured to select, from the nodes that have currently allocated the GTS time slot, a shared node to be GTS shared with the requesting node;

The functions of the second judging module 9022 and the assigning module 9023 are the same as those previously described, and are not described again.

It can be seen that, by adopting the technical solution of the embodiment of the present invention, after receiving the GTS request sent by each node, the network coordinator adaptively selects different GTS allocation modes by considering factors such as network traffic and delay, thereby achieving high efficiency. Reasonable allocation of network resources not only ensures the timely transmission of data in each node, but also greatly improves the utilization of GTS and optimizes network performance.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalents, improvements, etc., which are made within the spirit and principles of the present invention, should be included in the present invention. Within the scope of protection.

Claims

Claim

A time slot guarantee mechanism GTS time slot allocation method, characterized in that the method comprises:

2. The method according to claim 1, wherein the determining that the remaining time slots in the current superframe that can be used for GTS allocation cannot satisfy the GTS request request comprises: determining that the current superframe can be used for GTS allocation Whether the remaining time slot is less than the number of time slots requested to be allocated in the GTS request, and if so, determining that the remaining time slots in the current super frame that can be used for GTS allocation cannot satisfy the GTS request requirement.

The method according to claim 1, wherein the allocating the GTS time slot to the requesting node according to the shared GTS allocation manner includes:

The requesting node is allocated to share the GTS slot to which it is assigned with the node to which the GTS slot has been currently allocated.

The method according to claim 3, wherein the allocation requesting node shares the allocated GTS time slot with the node that has currently allocated the GTS time slot, including:

Determining whether there is currently a GTS time slot that is not occupied by other nodes, and if so, assigning the unoccupied GTS time slot to the requesting node, and then allocating the requesting node to the currently allocated GTS time slot. The node shares the GTS slot to which it is assigned; if it does not, it directly allocates the requesting node to share its assigned GTS slot with the node that has currently allocated the GTS slot.

The method according to claim 3 or 4, wherein the allocation requesting node shares the allocated GTS time slot with the node that has currently allocated the GTS time slot includes: Selecting one or more nodes from the nodes that have currently allocated the GTS time slots in descending order of GTS utilization as a shared node to be GTS shared with the requesting node;

Determining whether the requesting node and the shared node meet the GTS sharing requirement, if yes, assigning the requesting node to share the GTS allocated by the shared node with the shared node; otherwise, rejecting the GTS request.

The method according to claim 5, wherein the selecting one or more nodes as the shared node in descending order of GTS utilization includes:

Calculating the GTS utilization rate of each node that has currently allocated the GTS time slot, and determining whether the number of time slots included in the GTS allocated by the node with the lowest GTS utilization rate satisfies the GTS request requirement;

If yes, the node is selected as the shared node; otherwise, it is determined whether the sum of the number of time slots allocated by the node with the lowest GTS utilization rate and the node with the lowest GTS utilization rate satisfies the GTS request request, if still If not, continue to increase the number of nodes in order of low to high GTS utilization until the GTS request is met.

7. The method of claim 5, wherein

The GTS request carries the burst length, the data arrival rate, and the delay requirement information of the service of the requesting node;

The determining whether the requesting node and the shared node meet the GTS sharing requirement include:

Extracting burst length, data arrival rate, and delay requirement information of the service in the GTS request;

Determining, according to the burst length information of the service, the service delay of the requesting node and the shared node, and determining whether the service delay of the requesting node and the shared node is less than or equal to a respective delay requirement; If the service delay of the requesting node and the shared node are both less than or equal to the respective delay requirements, further determining whether the sum of the data arrival rates of the requesting node and the shared node is smaller than the relative bandwidth of the allocated GTS of the shared node, if If less than, the requesting node and the shared node satisfy the GTS sharing requirement.

8. The method of claim 5, wherein

The GTS request carries the allocation type information. Before the allocating the GTS time slot to the requesting node according to the shared GTS allocation manner, the method further includes:

And determining, according to the allocation type information carried in the GTS request, that the GTS slot is allowed to be allocated to the requesting node according to the shared GTS allocation manner.

The method according to claim 5, wherein the determining whether the requesting node and the sharing node meet the GTS sharing requirement further comprises:

Determining whether the shared node allows the requesting node to share the GTS allocated by the shared node, and if not, reselecting the shared node.

The method according to claim 1, wherein the GTS request comprises: a media access control MAC frame header MHR domain, a command frame identifier domain, and a GTS feature domain; the GTS feature domain includes an allocation type field, and a Send length field, data arrival rate field, and delay request field;

The burst length field, the data reaching rate field, and the delay requirement field are respectively used to identify a burst length, a data arrival rate, and a delay requirement information of the requesting node service;

The allocation type field is used to identify whether to allow a GTS slot to be allocated to the requesting node according to a shared GTS allocation manner.

11. The method of claim 10, wherein

If the allocation type field is identified as being allowed to allocate a GTS slot to the requesting node according to the shared GTS allocation manner, the burst length field, the data arrival rate field, and the delay are The request field is respectively provided with burst length, data arrival rate, and delay requirement information of the request node service;

Otherwise, the burst length field, data arrival rate field, and delay requirement field are set to null.

12. A GTS distribution device, the device comprising:

a shared GTS allocation module, configured to: when the judgment result of the first judging module is that the remaining time slots that can be used for GTS allocation in the current super frame cannot meet the GTS request requirement, use the shared GTS allocation manner as the requesting node. Assign GTS slots.

The device according to claim 12, wherein the shared GTS distribution module specifically includes:

a selection module, configured to: when the judgment result of the first judging module is that the remaining time slots that can be used for GTS allocation in the current super frame cannot meet the GTS request requirement, from the node that has currently allocated the GTS time slot Selecting a shared node to be GTS shared with the requesting node;

a second determining module, configured to determine whether the requesting node and the shared node selected by the selecting module meet the GTS sharing requirement;

An allocating module, configured to: when the determining result of the second determining module is that the requesting node and the sharing node meet the GTS sharing requirement, the node that allocates the initiating GTS request shares the sharing with the shared node The GTS to which the node is assigned; otherwise, the GTS request is rejected.

a third determining module, configured to: in the current superframe, the determination result of the first determining module is If the remaining time slots that can be used for the GTS allocation cannot satisfy the GTS request requirement, determine, according to the GTS request, whether the requesting node allows the GTS time slot to be allocated according to the shared GTS allocation manner;

a selection module, configured to: when the judgment result of the third judging module is that the requesting node allows the GTS time slot to be allocated according to the shared GTS allocation manner, select the request to be from the node that has currently allocated the GTS time slot a shared node that performs GTS sharing by the node; a second determining module, configured to determine whether the shared node selected by the requesting node and the selecting module meets a GTS sharing requirement;