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CN107222404B - A Parallel Path Forwarding Method with Redundant Coding in WOBAN - Google Patents

A Parallel Path Forwarding Method with Redundant Coding in WOBAN Download PDF

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CN107222404B
CN107222404B CN201710547442.1A CN201710547442A CN107222404B CN 107222404 B CN107222404 B CN 107222404B CN 201710547442 A CN201710547442 A CN 201710547442A CN 107222404 B CN107222404 B CN 107222404B
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CN107222404A (en
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张鸿
王汝言
吴光锴
杨衍
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Chongqing Xinxin Intelligent Technology Co ltd
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Chongqing University of Post and Telecommunications
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/24—Multipath
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/03—Arrangements for fault recovery
    • H04B10/032—Arrangements for fault recovery using working and protection systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/189—Transmission or retransmission of more than one copy of a message
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation
    • H04L45/121—Shortest path evaluation by minimising delays
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation
    • H04L45/124—Shortest path evaluation using a combination of metrics

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Abstract

本发明涉及一种带有冗余编码的并行路径转发方法，属于光无线融合网络通信技术领域。本发明针对现有WOBAN生存性保障方法业务数据丢失大，恢复成本高的问题，提出一种带有冗余编码的并行路径转发方法。本发明通过对原始业务数据包进行冗余编码并联合并行路径转发，在数据包转发过程中容忍配线光纤、ONU、无线节点和无线链路等故障。任意一条路径中的网路设备发生故障后，目的节点只需从其他路径接收足够的编码包即可恢复出原始数据，无需从新寻找路由，实现了快速无损的业务恢复。本发明在数据无损恢复的基础上降低了业务恢复成本，同时提升了业务恢复的速度。

Figure 201710547442

The invention relates to a parallel path forwarding method with redundant coding, which belongs to the technical field of optical wireless fusion network communication. Aiming at the problems of large loss of business data and high recovery cost in the existing WOBAN survivability guarantee method, the invention proposes a parallel path forwarding method with redundant coding. The present invention tolerates faults such as wiring optical fibers, ONUs, wireless nodes and wireless links in the data packet forwarding process by redundantly encoding original service data packets and forwarding them in conjunction with parallel paths. When a network device in any path fails, the destination node only needs to receive enough encoded packets from other paths to recover the original data without having to find a new route, realizing fast and lossless service recovery. The invention reduces the cost of business recovery on the basis of data lossless recovery, and at the same time improves the speed of business recovery.

Figure 201710547442

Description

Parallel path forwarding method with redundant coding in WOBAN
Technical Field
The invention belongs to the technical field of optical wireless converged network communication, and relates to a parallel path forwarding method with redundant coding in WOBAN.
Background
With the increasing popularization of intelligent terminal devices, various mobile applications and multimedia services are continuously enriched, the demand of users for high bandwidth is rapidly increased, and the traditional access mode cannot meet the increasing bandwidth demand. An Optical-Wireless convergence-Access Network (WOBAN) that combines the advantages of both Optical networks and Wireless networks is considered to be the most ideal and efficient Access Network solution in the future.
WOBAN is a novel access Network architecture composed of a Passive Optical Network (PON) with large capacity at the back end and a Wireless Mesh Network (WMN) with flexible access at the front end. The PON at the back end has the characteristics of large bandwidth, low loss and high reliability, the WMN at the front end has the characteristics of easiness in deployment, low cost and high flexibility, and as a fusion network of the PON and the WMN, the WOBAN can provide faster and more efficient service for users. However, as the amount of traffic increases, a great amount of data is lost due to a fault in any one of the networks, such as a trunk Fiber (FF), a Distribution Fiber (DF), an Optical Network Unit (ONU), a Wireless Link (WL), etc., resulting in a great amount of service interruption. As an access network directly facing terminal users, the subjective experience of the users is seriously influenced by any network fault. Therefore, a fast and efficient survivability guarantee mechanism plays a crucial role for WOBAN.
Currently, the research on survivability guarantee technology in WOBAN is mainly divided into two main categories. The first type is that the self-healing of the wireless front-end mesh network is utilized to search an available route in the WMN to forward the service data affected by the fault, and the research can solve the faults of devices such as distribution optical fibers, ONUs, wireless nodes, wireless links and the like. Y Liu, J Wu, Y Yu, Z Ning, etc. put forward a Wireless Rerouting algorithm (WRBR) in "Deployment of flexible fiber-Wireless access for converted Optical fiber networks" [ Optical Switching and Networking,2014,14(8): 226:232 ], allocates a spare for ONU, and reserves a spare resource for ONU in the spare ONU to solve the problem of single wiring fiber fault. Thota S, bhamutik P, Chowdhury P, etc. propose a Risk-and-Delay-Aware Routing protocol (RADAR) [ (ieee network,2013,27(4):72-79 ]) in "expanding wireless connectivity for robust inbound Routing", and the wireless Routing node timely senses the network failure by actively maintaining a Risk list, and reduces the rerouting path switching time after the failure by Delay sensing to reduce the data loss. Although the method does not need extra cost, the recovery route needs to be searched again after the fault, long recovery time is needed, and a large amount of service data can be lost.
Another type of research is to transfer the traffic data affected by the failure by adding extra spare fiber or spare radios. Such studies can address failures of equipment such as OLT, trunk fiber, distribution fiber, ONU, wireless node, and wireless link. Y Liu, L Guo, X Wei proposes an optimized Selection of spare ONUs and Deployment of spare Fibers (Optimizing Back ONUs Selection and spare Fibers Deployment mechanism, OBOF) in "Optimizing Back Optical-Network-Units Selection and Secondary Fibers Deployment in simplified fiber optics-Optical broadband Access Networks" [ Journal of Lightwave Technology,2012,30(10),1509-1523 ], to optimize Selection of spare ONUs and Deployment of spare Fibers using simulated annealing algorithm for the purpose of minimizing recovery cost. L Guo, Y Liu, F Wang et al propose a Cluster-based protection mechanism (CBP) in "Cluster-based protection for virtual fiber-wireless access networks" [ Journal of optical communication and Networking,2013,5(11): 1178-based protection, 1194 ], adopt heuristic algorithm and linear programming model to Cluster the network ONU, and consider the selection of spare fiber and the deployment problem of spare fiber at the same time. Although the method reserves the standby resources and can quickly recover the service data affected by the fault, the method needs to deploy additional standby optical fibers, and the recovery cost is higher.
Although the above research can quickly recover the service data affected by the failure, even a short service terminal can cause a large amount of service data to be lost, and the deployment of the spare fiber also increases the cost of failure recovery. Therefore, how to reduce the loss of business data and how to reduce the cost of failure recovery is the key to designing the survivability guarantee mechanism in WOBAN.
Disclosure of Invention
In view of the above, the present invention is directed to a parallel path forwarding method with redundant coding in WOBAN. Aiming at the problems of large loss of service data and high recovery cost of the existing WOBAN survivability guarantee method, the invention calculates the number of parallel paths meeting the requirement according to the service reliability requirement and calculates the parallel path with the minimum time delay according to the queuing theory. And then, coding the service data packet by using redundant coding at the source node, and calculating an optimal flow distribution scheme and a coding packet number according to parameters such as the path number, the packet loss rate and the like. When the destination node receives enough linearly independent coding packets from a plurality of parallel paths, the original service data can be recovered. The invention carries out redundancy coding and parallel connection and path forwarding on the original service data packet, and tolerates faults of DF, ONU, wireless nodes, wireless links and the like in the data packet forwarding process. After the network equipment in any path fails, the destination node can recover the original data only by receiving enough coding packets from other paths without searching for a new route, thereby realizing rapid and lossless service recovery. Compared with other methods, the method reduces the service recovery cost on the basis of data lossless recovery, and simultaneously improves the service recovery speed.
In order to achieve the purpose, the invention provides the following technical scheme:
the parallel path forwarding method with redundant coding in WOBAN includes link state broadcasting stage, link weight value distributing stage, parallel path calculating stage and redundant coding transmission stage,
in the link state broadcasting stage, the wireless routing node and the ONU broadcast the link state information to the network;
in the link weight value distribution stage, the wireless routing node and the ONU calculate the time delay of the optical fiber and the wireless link according to the parameters in the link state information, and set the time delay as the weight value of the link;
in the parallel path calculation stage, the wireless routing node and the ONU calculate the number N of parallel paths meeting the service requirement according to the reliability requirement of the service and the error rates of the optical fiber and the wireless link, and repeatedly calculate N parallel paths with minimum time delay by using a Dijkstra shortest path algorithm;
and in the redundant coding transmission stage, the wireless routing node and the ONU calculate the optimal coding packet flow distribution scheme and the optimal number coding data packet number M, perform redundant coding and transmit the redundant coding to the destination node through a parallel path.
Further, the link state information includes parameters: node type, node identification, exit link group, data packet density, packet loss rate, queue length and timestamp.
Further, the broadcasting of the link state information to the network by the wireless routing node and the ONU node specifically includes:
and the wireless routing node sends the link state information to the wireless routing node and the ONU, and the ONU simultaneously sends the link state information to the wireless routing node, the ONU and the OLT.
Further, the calculating the time delay of the optical fiber and the wireless link specifically includes:
the uplink time delay from ONU to OLT is TONU,OLT＝TR+TG+TS+TQ+TPWherein T isRFor the time between the arrival of a packet and the sending of the first Request message, TGFor the time between the transmission of the first Request message and the reception of the Grant message transmitting the data packet, TSWaiting for the time of transmitting data in the authorized time slot T after receiving the Grant information of the data packetQTime, T, required for transmitting data before the data packet in the queue after the authorized time slot arrivesPThe propagation delay of the data packet on the optical fiber link is determined;
queue length of ONU
Figure BDA0001343521200000031
In which
Figure BDA0001343521200000032
Obtaining the mean value of authorized bandwidth for the ONU, and the uplink time delay from the ONU to the OLT is
Figure BDA0001343521200000033
Wherein E [ Tcycle]Is a polling period TcycleMean value of ROThe transmission rate of the optical fiber is shown, and RTT is the round trip delay of the ONU;
queue length of ONU
Figure BDA0001343521200000034
The uplink time delay from ONU to OLT is
Figure BDA0001343521200000035
Wherein WMAXIs the maximum authorized bandwidth.
Further, said E [ T ]cycle]The calculation method comprises the following steps:
firstly, the bandwidth applied by any ONU in the next period is solved according to the queuing theory
Figure BDA0001343521200000041
Wherein Vi(k +1) represents ONUiAt the application bandwidth of k +1 polling periods,
Figure BDA0001343521200000042
for ONUiOf the kth polling period length, λiThe arrival rate of the data packets, wherein 1/mu is the average length of the data packets;
then according to the size E [ V ] of the bandwidth applied by ONU in the next periodi(k+1)]The ONUs are divided into 2 groups: high Load ONU (HLONU) and Low Load ONU (LLONU), wherein the ONU in the set HLONU satisfies E [ V ]i(k+1)]＞WMAXThat is, the requested bandwidth of ONU is greater than the maximum authorized bandwidth, and the ONU in the set LLONU satisfies E [ V ]i(k+1)]≤WMAXThat is, the authorized bandwidth of the ONU is less than or equal to the maximum authorized bandwidth; when in use
Figure BDA0001343521200000043
And is
Figure BDA0001343521200000044
When it is, all ONU are in low load state and satisfy EVi(k+1)]≤WMAXMean value of polling period
Figure BDA0001343521200000045
When in use
Figure BDA0001343521200000046
And is
Figure BDA0001343521200000047
Mean of time, polling period
Figure BDA0001343521200000048
When in use
Figure BDA0001343521200000049
And is
Figure BDA00013435212000000410
When it is time, i.e. all ONUs are in a high load state and satisfy evi(k+1)]＞WMAXMean value of the polling period E [ T ]cycle]＝K(WMAX+Tg) Wherein T isgAnd K is the number of the ONU in the network.
Further, the
Figure BDA00013435212000000411
Satisfies the following conditions: when ONUiWhen the element belongs to LLONU, namely ONU belongs to low-load ONU, mean value of authorized bandwidth
Figure BDA00013435212000000412
When ONUiWhen belonging to HLONU, namely ONU belongs to high-load ONU, mean value of authorized bandwidth
Figure BDA00013435212000000413
Further, the calculating the number N of parallel paths meeting the service requirement specifically includes: for any one parallel path P, include
Figure BDA00013435212000000414
A hop wireless link and a 1-hop optical fiber link, wherein
Figure BDA00013435212000000415
The average value of the hop counts from the wireless routing node to different ONU is calculated by formula
Figure BDA00013435212000000416
Get, | W | is the number of ONU in the network, hiThe number of the shortest hops from the wireless routing node to the ith ONU is obtained; probability of successful transmission of data packet to destination node in any one parallel path P
Figure BDA00013435212000000417
Is composed of
Figure BDA00013435212000000418
Wherein
Figure BDA00013435212000000419
Is the bit error rate of the wireless link,
Figure BDA00013435212000000420
the bit error rate of the optical fiber link, L is the data packet length; reliability of the N parallel paths
Figure BDA00013435212000000421
According to the reliability R of the service requirement, the number N of the parallel paths passes through a formula
Figure BDA0001343521200000051
Thus obtaining the product.
Further, the calculating of the optimal coding packet traffic distribution scheme specifically includes: when x is1＝x2＝…＝xk＝…＝xNWhere x is M/NkIndicating the number of coded data packets transmitted in the kth parallel path, xNThe number of the coded data packets transmitted in the Nth parallel path is represented, namely the number of the coded data packets on each parallel path is equal, and the number M of the required coded data packets is minimum on the basis that the destination node successfully decodes and recovers the original data packets after any one parallel path fails; where M is the number of encoded packets and N is the number of parallel paths.
Further, the method for calculating the number M of the optimal number encoded data packets comprises:
when the packet loss of the wireless link is not considered, the total number of the coded data packets transmitted in any N-1 paths is greater than or equal to m, namely
Figure BDA0001343521200000052
Wherein M is the number of the encoding packets, M is the number of the original data packets, and N is the number of the parallel paths; the target node recovers the original data after any one parallel path failsEncoding the minimum number of data packets M on the packet basis
Figure BDA0001343521200000053
Meanwhile, according to the flow distribution scheme, the destination node at least receives m/N-1 coded data packets from each parallel path to successfully decode the original data packets;
when considering the packet loss of the wireless link, let EiIs path Pi＝{e1,e2…, the packet loss rate of the ith link is that for any packet, the probability of successful transmission to the destination node is
Figure BDA0001343521200000054
X'iIn order to consider the number of the coded data packets transmitted by the ith path after the packet loss rate, the node at least receives m/N-1 coded data packets from each parallel path
Figure BDA0001343521200000055
Obtaining the number of the coding data packets at least transmitted on each parallel path
Figure BDA0001343521200000056
The total number of coded data packets M is
Figure BDA0001343521200000057
Further, the performing the redundant coding and transmitting to the destination node through the parallel path specifically includes: grouping data packets to be sent by a source node according to M data packets in each group, performing redundant coding on the data packets in each group to generate M coded data packets, and then transmitting the coded data packets to a destination node through N parallel paths according to a flow distribution scheme; the destination node receives m linearly independent coded packets from the N parallel paths, decodes and recovers m original data packets; when any one parallel path fails, according to the coding scheme, the destination node receives at least m linearly independent coded packets from other N-1 parallel paths.
The invention has the beneficial effects that: the survivability guarantee method provided by the invention carries out redundant coding on the original data packet, eliminates the dependence of the service on a single data packet, and when the single data packet is lost, the source node does not need to retransmit, but the target node can still successfully recover the original data packet; the method combines the parallel paths to transmit the coding packets, and considers that the number of the parallel paths and the number of the redundant coding packets are calculated under the condition that a target node can still succeed after any one parallel path fails, so that the method can tolerate the interruption of the whole path caused by the equipment failure on any one path, compared with other methods, the method does not need to retransmit data packets, and can quickly recover the original data packets; the method does not need to add extra standby optical fibers or standby wireless transceiving equipment, and greatly reduces the network deployment cost.
Drawings
In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:
FIG. 1 is a diagram of a network architecture of WOBAN;
FIG. 2 is a flow chart of a parallel data forwarding method with redundant coding;
fig. 3 is a schematic diagram of an ONU and an OLT interaction;
fig. 4 is a schematic diagram of an ONU internal queue;
fig. 5 is a schematic diagram of a polling cycle.
Detailed Description
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
The method protects the distribution optical fiber fault, the ONU fault, the wireless node and the link fault in the WOBAN and recovers data quickly and nondestructively by fusing redundant coding parallel path forwarding and using lower time delay and less resources. The network structure of the WOBAN network is shown in fig. 1. The method mainly comprises the following steps, as shown in fig. 2.
1. A link state broadcasting stage: the nodes (ONU and wireless routing node) periodically broadcast Link State information (LSA) into the network, the format of which is shown in table 1. Meanwhile, the ONU needs to send the received LSA of the wireless routing node to the OLT, so that the OLT selects a proper parallel path for transmission during downlink data transmission.
TABLE 1 LSA packet format
Figure BDA0001343521200000061
Wherein:
1) the node type is Router or ONU;
2) the node identification is the unique identification of the node in the network;
3) the egress link group is all egress links starting from the node. If the node type is Router, the part comprises all exit links taking the wireless routing node as a starting point; if the node type is ONU, the part comprises an optical fiber link from the ONU to the OLT and a wireless link from the ONU as a starting point to a wireless routing node;
4) the data packet density is the density of data packet arrival on a wireless link or an optical fiber link;
5) the packet loss rate is an average packet loss rate of the link, the packet loss rate of the wireless link can be obtained by sending a detection packet, and the packet loss rate of the optical fiber link is set to be 0 because the optical fiber link is stable.
6) The queue length is the length of the ONU internal queue, and the field is NULL when the node type is Router.
7) The timestamp is the time that the LSA was generated, assuming that the time of the entire network remains synchronized.
The LSAs generated by the wireless routing node and the ONU are shown in table 2 and table 3.
TABLE 2 LSA generated by Wireless routing node
Figure BDA0001343521200000071
TABLE 3 ONU generated LSA
Figure BDA0001343521200000072
2. A link weight value distribution stage: when a service needs to be transmitted, a source node first needs to update the weight of each link in the network according to the LSA of each node, and the method calculates the time delay of each link according to the parameters in the LSA and sets the time delay as the weight of the link.
1) Radio link delay
Assuming that a wireless routing node of a WOBAN wireless front end shares a channel in a TDMA manner, the time delay of a wireless link of a data packet in a WMN mainly includes four aspects: propagation delay, transmission delay, slot synchronization delay, and queuing delay.
The time delay d for any one of the radio links u-vuvCan be calculated by equation (1).
Figure BDA0001343521200000073
Wherein 1/μ represents the average packet length, CuvRepresents the effective capacity, λ, of the link u-vuvIs the packet density on link u-v.
2) Optical fiber link delay
According to a Dynamic Bandwidth Allocation algorithm (DBA), uplink transmission of a PON network at the back end of the WOBAN transmits data in a time division multiplexing manner, and downlink transmission transmits data in a broadcasting manner.
① upstream time delay from ONU to OLT
During uplink transmission, all ONUs share an uplink channel in a time division multiplexing mode, and each ONU can only send uplink data and Request information in a time slot authorized by the OLT. The Request information includes the queue length of the ONU, and indicates the bandwidth that the ONU expects to transmit in the next polling cycle. Assuming that the scheduling of the ONU internal queue adopts the FIFO mechanism, according to the DBA algorithm, after a data packet arrives at the ONU, the whole interaction process of the ONU and the OLT is as shown in fig. 3.
The total delay T of the data packet from the ONU to the OLTONU,OLTAs shown in equation (2).
TONU,OLT＝TR+TG+TS+TQ+TP(2)
TRFor packet arrival and transmission firstThe time between Request messages. The mean value can be calculated by equation (3), where TcycleIs a polling period.
E[TR]＝E[Tcycle]/2 (3)
TGThe time between the sending of the first Request message and the receiving of the Grant message that can send the data packet. As shown in fig. 4, when the load is high, when a packet arrives, there are many packets in the queue, and in one polling period, the ONU cannot transmit all the packets, so T is TGPossibly containing multiple polling periods. If the ONU does not send out all the data packets in the queue, the ONU must be granted the maximum authorized bandwidth W at the momentMAXThen T isGThe mean value of (c) can be calculated by equation (4).
Figure BDA0001343521200000081
Wherein q is the queue length of the ONU,
Figure BDA0001343521200000082
and indicating the authorized bandwidth contained in the received Grant information before the first Request information is sent after the data packet arrives at the ONU.
Figure BDA0001343521200000083
An average of the licensed bandwidth is obtained for the ONU.
TSWaiting for the time of transmitting data in the authorized time slot after receiving the Grant information of the data packet, wherein the DBA algorithm only transmits the Grant information before the authorized time slot of the ONU arrives, so that TSVery small and negligible.
TQAnd after the authorized time slot arrives, sending the data before the data packet in the queue. T isQCan be calculated by the formula (5) wherein ROIs the transmission rate of the optical fiber.
Figure BDA0001343521200000084
TPIs the propagation delay of the data packet on the optical fiber link. The mean value is shown in equation (6), where RTT is the round trip delay of ONU.
E[TP]＝RTT/2 (6)
Therefore, the total upstream delay T of the data packet from the ONU to the OLTONU,OLTCan be expressed as equation (7).
Figure BDA0001343521200000091
In equation (7), the mean value E [ T ] due to the length of the polling periodcycle]And mean of granted bandwidth
Figure BDA0001343521200000092
Unknown, so that the uplink time delay can not be obtained temporarily, the invention uses the queuing theory to calculate the ETcycle]And
Figure BDA0001343521200000093
suppose that the data packet arrival of the ith ONU obeys Poisson distribution and the arrival rate is lambdaiThe average length of the data packet is 1/mu, Wi(k) For ONUiGranted Bandwidth in the kth Polling cycle, Vi(k) For ONUiBandwidth, N, applied to OLT in kth polling periodi(T) indicates ONUiThe number of packets arriving within time T. As shown in fig. 5, the ONUiHas a k-th polling period length of
Figure BDA0001343521200000094
Assuming that the bandwidth size applied to the OLT in the (k +1) th polling period is mainly determined by the amount of data arriving in the previous polling period, as shown in fig. 5, the ONU1The data packet arriving in the 0 th polling period of (2) applies for bandwidth from the OLT in the 1 st polling period.
For ONUiThe probability that the number of arriving packets in the kth polling period is n is shown in equation (8).
Figure BDA0001343521200000095
Then the ONUiThe average of the number of arriving packets in the kth polling period is shown as the indicator (9).
Figure BDA0001343521200000096
In the k +1 polling period, ONUiThe bandwidth size of the application is shown in formula (10).
Figure BDA0001343521200000097
According to the LSA of all the ONUs, the E [ V (k +1) of any one ONU can be calculated]. All ONUs are divided into two groups: high Load ONU (HLONU) and Low Load ONU (Low Load ONU, LLONU). Wherein an ONU in the set HLONU satisfies EVi(k+1)]＞WMAXONU in LLONU satisfies EVi(k+1)]≤WMAX。
a) When in use
Figure BDA0001343521200000098
And is
Figure BDA0001343521200000099
When it is, all ONU are in low load state and satisfy EVi(k+1)]≤WMAX。
At the moment, the network load is small, and the ONUiThe granted bandwidth obtained in the (k + 2) th polling period should be equal to the bandwidth requested in the (k +1) th polling period, i.e. as shown in equation (11).
E[Wi(k+2)]＝E[Vi(k+1)](11)
The length of the (K + 2) th polling period can be expressed as a public indication (12), where K is the number of ONUs and T is the number of ONUsgIndicating a guard time slot.
Figure BDA0001343521200000101
At steady state, the average of the different polling period lengths should be equal, i.e.
Figure BDA0001343521200000102
Equation (12) can be simplified to.
Figure BDA0001343521200000103
Thus, the mean value E [ T ] of the polling period can be obtainedcycle]Is shown in equation (15).
Figure BDA0001343521200000104
b) When in use
Figure BDA0001343521200000105
And is
Figure BDA0001343521200000106
Then (c) is performed.
ONUiGranted Bandwidth E [ W ] obtained at the k +2 polling periodi(k+2)]Equation (16) should be satisfied.
Figure BDA0001343521200000107
The k +2 th polling period length is shown in equation (17).
Figure BDA0001343521200000108
Similarly, in steady state, the average of the lengths of different polling periods should be equal, and the above equation can be simplified to equation (18). Wherein | HLONU | is the number of nodes in the set HLONU.
Figure BDA0001343521200000109
c) When in use
Figure BDA00013435212000001010
And is
Figure BDA00013435212000001011
When it is time, i.e. all ONUs are in a high load state and satisfy evi(k+1)]＞WMAX。
ONUiThe granted bandwidth obtained at the k +2 polling period is shown in equation (19).
E[Wi(k+2)]＝WMAX(19)
The mean value of the polling period E [ T ] can be obtained in the same waycycle]Is as follows.
Figure BDA0001343521200000111
In summary, the ONUiMean value of polling period length E [ T ]cycle]Is shown in equation (21).
Figure BDA0001343521200000112
ONUiMean of granted bandwidths
Figure BDA0001343521200000113
Is shown in equation (22).
Figure BDA0001343521200000114
According to the formula (22), the formula (23) and the formula (7), the uplink time delay T from the ONU to the OLT can be obtainedONU,OLT。
② downstream delay from OLT to ONU
The downstream delay from the OLT to the ONU includes transmission delay and propagation delay. When the link capacity between the OLT and each ONU is equal, the transmission delay to each ONU is equal for any one packet, and therefore the transmission delay is not considered herein. The downlink delay TOLT,ONUAs shown in equation (23)Shown in the figure.
Figure BDA0001343521200000115
Wherein
Figure BDA0001343521200000116
For OLT to ONUiOf the optical fiber link length SopticalIs the propagation speed of an optical signal in an optical fiber.
3. A parallel path calculation stage: the invention repeatedly utilizes Dijkstra shortest path algorithm to find out the parallel path separated by the ONU with the minimum time delay.
1) Calculating the number of parallel paths N
Let the reliability of the service requirement be R, and the error rate of each wireless link be the same as
Figure BDA0001343521200000117
The error rate of each optical fiber link is the same as
Figure BDA0001343521200000121
Each packet is the same length and is L. Probability P of error-free transmission of data packets over the radio linkwIs as follows.
Figure BDA0001343521200000122
Similarly, probability P of error-free transmission of data packets over an optical fiber linkoIs as follows.
Figure BDA0001343521200000123
Because the hop counts from the wireless routing node to different ONUs are different, in order to simplify the operation, the method is provided
Figure BDA0001343521200000124
Is the average value of the number of hops from the wireless routing node to different ONUs, as shown in equation (26), where | W | is the number of ONUs in the network, hiRouting nodes to ith O for wirelessThe shortest hop count of NU.
Figure BDA0001343521200000125
For any path P, include
Figure BDA0001343521200000126
Probability of successful transmission of data packet to destination node by hopping radio link and 1-hop optical fiber link
Figure BDA0001343521200000127
Is composed of
Figure BDA0001343521200000128
Because the faults of the distribution optical fiber, the ONU, the wireless node, the wireless link and the like all cause the failure of one path, the destination node can still successfully decode the original data packet after considering that any path fails. Therefore, at least N-1 paths are successfully transmitted, and the destination node can successfully decode the original data packet. The reliability R' of the N parallel paths is shown in equation (28).
Figure BDA0001343521200000129
The reliability of the N parallel paths should satisfy R' being equal to or more than R, so that
Figure BDA00013435212000001210
The number N of parallel paths satisfying the reliability R can be obtained from the bulletin (29).
2) Finding N parallel paths
First, an auxiliary graph G' is initialized, which contains all the optical fiber links as well as the wireless links. In G ', a Dijkstra shortest path algorithm is used for calculating a 1 st path from a source node to a destination node (from a wireless routing node to an OLT or in the opposite direction), and then G ' is updated, and links (both bidirectional links are deleted) between nodes, which are passed by the 1 st path, are deleted in G '. And (4) continuously using Dijkstra shortest path algorithm to calculate the 2 nd path in the updated G', and circulating for N times, thus calculating the parallel paths separated by the N ONUs.
4. And a redundancy coding transmission stage: the source node encodes M original data packets into M encoded data packets by using redundancy coding, and transmits the data packets to N parallel paths according to a data packet flow distribution scheme. And if the intermediate node is a cross node of a plurality of paths, recoding the K coded data packets received in the same group within a short time tau. And when the target node receives m linear irrelevant coded data packets from the N parallel paths, the original data packets can be successfully decoded and recovered.
1) Optimal data packet traffic allocation scheme
The flow distribution problem of the coded data packets is how to distribute the M coded data packets into N paths. Because the coded data packets on the whole path cannot be transmitted to the OLT after the distribution optical fiber, the ONU or the wireless link, etc. have a fault, the flow distribution in the N paths has differences, and the number of the data packets on each path is different, so the number of the lost coded data packets is also different. In order to ensure that the OLT can receive M linearly independent encoded data packets after a system failure, the number M of the required encoded data packets is different under different traffic allocation schemes. Meanwhile, under the condition of the same number M of encoded data packets, different traffic allocation schemes will also affect whether the OLT can successfully receive M linearly independent encoded data packets.
Therefore, the main objective of the present invention is to find the optimal flow distribution scheme to minimize the number M of encoded data packets on the basis of ensuring that the OLT can successfully decode and recover the original data packets in the case of a failure of the distribution optical fiber, the ONU and the wireless link.
Assuming that M original data packets are provided, M encoded data packets are generated after random linear network encoding, and all the encoded data packets are linearly independent. n iskRepresenting the kth parallel path, xkRepresenting parallel paths nkCoded data packet of upper transmissionAnd (4) counting. Then it is shown in formula (30).
x1+x2+…+xk+…+xN＝M,1≤k≤N (30)
It is assumed that after the distribution optical fiber, the ONU or the wireless link in any path fails, all the encoded data packets transmitted on the path will be lost. Meanwhile, the number of data packets in the parallel path is arranged in an ascending order, as shown in formula (31).
0＜x1≤x2≤…≤xk≤…≤xN＜M,1≤k≤N (31)
According to the formula (30) and the formula (31) have
x1+x2+…+xk+…+xN＝M≤N·xN(32)
Can obtain
xmax＝xN≥M/N (33)
By the same token can obtain
xmin＝x1≤M/N (34)
Under the condition of not considering link packet loss, when any one of the N parallel paths fails, the destination node can still decode and recover the original data, and the total number of the coded data packets transmitted in any N-1 paths is greater than or equal to m.
When the path nNAfter failure, to ensure that the destination node can decode successfully, the total number of the encoded data packets transmitted on the other N-1 links should satisfy the formula (35).
x1+x2+…+xk+…+xN-1＝M-xN≥m (35)
Namely, it is
M≥m+xN≥m+M/N (36)
Thus, when x can be obtainedNWhen M/N, the number of encoded data packets M can be minimized.
In the same way, a formula (37) can be obtained, that is, when the number of the encoded data packets on each parallel path is equal, the number M of the encoded data packets is the minimum on the basis that the destination node can successfully decode and recover the original data packet after any one parallel path fails.
x1＝x2＝…＝xk＝…＝xN＝M/N (37)
2) Number of optimal number encoded data packets M
Let P be { P ═ P1,P2,…,PNIs a set of N parallel paths, where Pi＝{e1,e2… is the link set of the ith parallel path. When the packet loss of the wireless link is not considered, the total number of the coded data packets transmitted in any N-1 paths should be greater than or equal to m, and the formula (38) can be obtained according to the formula (35) and the formula (37).
Figure BDA0001343521200000141
Namely:
Figure BDA0001343521200000142
in order to reduce the network load, the minimum value of M, i.e., the minimum value of the number M of encoded data packets, is shown in equation (40).
Figure BDA0001343521200000143
The number of data packets transmitted on each path is equal to
Figure BDA0001343521200000144
Because each wireless link has a condition of packet loss (assuming that there is no packet loss in the optical fiber link), when packet loss occurs, the destination node receives fewer than m encoded data packets from N-1 paths, and thus cannot successfully decode, so that in order to enable the destination node to successfully decode after a transmission failure, the destination node should still receive at least m encoded data packets after packet loss.
The destination node should receive at least m/N-1 encoded data packets from each parallel path, and therefore, the number of encoded data packets transmitted on each parallel path must be increased for the packet loss situation on each parallel path, so that the destination node can receive at least m/N-1 encoded data packets on each parallel path.
Let EiIs path Pi＝{e1,e2…, the packet loss rate of the ith link is shown in formula (42) for any data packet, the probability of successful transmission to the destination node is shown.
Figure BDA0001343521200000151
X'iIn order to consider the number of encoded data packets transmitted on the ith path after the packet loss rate, the number of data packets successfully reaching the destination node should be greater than or equal to m/N-1, as shown in formula (43).
Figure BDA0001343521200000152
According to the formula (44), at least the number of the coded data packets to be transmitted on each parallel path can be obtained
Figure BDA0001343521200000153
The total number M of coded packets is shown in equation (45) in consideration of packet loss.
Figure BDA0001343521200000154
3) Performing redundant coding
The source node groups the data packets to be sent according to m data packets in each group, and respectively uses X data packets1,X2,…,XmTo represent the m original packets. From a finite field FqWherein M groups of random numbers are randomly selected to form coding coefficients, and each group comprises M random numbers to form a coding vector ai＝(ξ1,ξ2,……,ξm). By Y1,Y2,…,YMRepresenting M encoded packets, where M > M.The encoding process can be expressed as shown in equation (46).
Figure BDA0001343521200000155
After the M coded data packets are generated, the source node transmits the M coded data packets to the destination node through the N paths. After the destination node receives the m linearly independent coded data packets, the original data packet can be recovered according to a formula (47).
Figure BDA0001343521200000156
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims (6)

1. The parallel path forwarding method with redundant coding in the WOBAN of the optical wireless convergence access network comprises a link state broadcasting stage, a link weight value distribution stage, a parallel path calculation stage and a redundant coding transmission stage, and is characterized in that:
in the link state broadcasting stage, the wireless routing node and the optical network unit ONU broadcast the link state information to the network;
in the link weight value distribution stage, the wireless routing node and the ONU calculate the time delay of the optical fiber and the wireless link according to the parameters in the link state information, and set the time delay as the weight value of the link;
in the parallel path calculation stage, the wireless routing node and the ONU calculate the number N of parallel paths meeting the service requirement according to the reliability requirement of the service and the error rates of the optical fiber and the wireless link, and repeatedly calculate N parallel paths with minimum time delay by using a Dijkstra shortest path algorithm;
in the redundant coding transmission stage, the wireless routing node and the ONU calculate an optimal coding packet flow distribution scheme and an optimal number coding data packet number M, then carry out redundant coding and transmit the redundant coding to a target node through a parallel path;
the broadcasting of the link state information to the network by the wireless routing node and the ONU node is specifically as follows:
the wireless routing node sends the link state information to the wireless routing node and the ONU, and the ONU sends the link state information to the wireless routing node, the ONU and the OLT simultaneously;
the calculating of the parallel path number N meeting the service requirement specifically includes: for any one parallel path P, include
Figure FDA0002421476040000011
A hop wireless link and a 1-hop optical fiber link, wherein
Figure FDA0002421476040000012
The average value of the hop counts from the wireless routing node to different ONU is calculated by formula
Figure FDA0002421476040000013
Get, | W | is the number of ONU in the network, hiThe number of the shortest hops from the wireless routing node to the ith ONU is obtained; probability of successful transmission of data packet to destination node in any one parallel path P
Figure FDA0002421476040000014
Is composed of
Figure FDA0002421476040000015
Wherein P ise wIs the bit error rate, P, of the radio linke oThe bit error rate of the optical fiber link, L is the data packet length; reliability of the N parallel paths
Figure FDA0002421476040000016
According to the reliability R of the service requirement, the number N of the parallel paths passes through a formula
Figure FDA0002421476040000017
Obtaining;
the optimal coding packet flow distribution scheme is specifically as follows: when x is1＝x2＝…＝xk＝…＝xNWhere x is M/NkIndicating the number of coded data packets transmitted in the kth parallel path, xNThe number of the coded data packets transmitted in the Nth parallel path is represented, namely the number of the coded data packets on each parallel path is equal, and the number M of the required coded data packets is minimum on the basis that the destination node successfully decodes and recovers the original data packets after any one parallel path fails; wherein M is the number of the coding packets, and N is the number of the parallel paths;
the method for calculating the optimal number coded data packet number M comprises the following steps:
when the packet loss of the wireless link is not considered, the total number of the coded data packets transmitted in any N-1 paths is greater than or equal to m, namely
Figure FDA0002421476040000021
Wherein M is the number of the encoding packets, M is the number of the original data packets, and N is the number of the parallel paths; obtaining the minimum value of the number M of the coded data packets on the premise that the destination node recovers the original data packet after any one parallel path fails
Figure FDA0002421476040000022
Meanwhile, according to the flow distribution scheme, the destination node at least receives m/N-1 coded data packets from each parallel path to successfully decode the original data packets;
when considering the packet loss of the wireless link, let EiIs path Pi＝{e1,e2…, the packet loss rate of the ith link is that for any packet, the probability of successful transmission to the destination node is
Figure FDA0002421476040000023
X'iIn order to consider the number of coded data packets transmitted on the ith path after the packet loss rate, the nodes are arranged from each pathAt least m/N-1 coded data packets are received on the parallel path
Figure FDA0002421476040000024
Obtaining the number of the coding data packets at least transmitted on each parallel path
Figure FDA0002421476040000025
The total number of coded data packets M is
Figure FDA0002421476040000026
2. The method of parallel path forwarding with redundant coding in WOBAN according to claim 1, characterized in that: the link state information includes parameters: node type, node identification, exit link group, data packet density, packet loss rate, queue length and timestamp.
3. The method of parallel path forwarding with redundant coding in WOBAN according to claim 1, characterized in that: the calculating of the time delay of the optical fiber and the wireless link specifically comprises:
the uplink time delay from ONU to OLT is TONU,OLT＝TR+TG+TS+TQ+TPWherein T isRFor the time between the arrival of a packet and the sending of the first Request message, TGFor the time between the transmission of the first Request message and the reception of the Grant message transmitting the data packet, TSWaiting for the time of transmitting data in the authorized time slot T after receiving the Grant information of the data packetQTime, T, required for transmitting data before the data packet in the queue after the authorized time slot arrivesPThe propagation delay of the data packet on the optical fiber link is determined;
queue length of ONU
Figure FDA0002421476040000027
In which
Figure FDA0002421476040000028
Obtaining the mean value of authorized bandwidth for the ONU, and the uplink time delay from the ONU to the OLT is
Figure FDA0002421476040000029
Wherein E [ Tcycle]Is a polling period TcycleMean value of ROThe transmission rate of the optical fiber is shown, and RTT is the round trip delay of the ONU;
queue length of ONU
Figure FDA0002421476040000031
The uplink time delay from ONU to OLT is
Figure FDA0002421476040000032
Wherein WMAXIs the maximum authorized bandwidth.
4. A method of parallel path forwarding with redundant coding in WOBAN according to claim 3, characterized in that: said E [ T ]cycle]The calculation method comprises the following steps:
firstly, the bandwidth applied by any ONU in the (k +1) th polling period is solved according to the queuing theory
Figure FDA0002421476040000033
Wherein Vi(k +1) represents ONUiAt the application bandwidth of k +1 polling periods,
Figure FDA0002421476040000034
for ONUiOf the kth polling period length, λiIn order to be able to determine the packet arrival rate,
Figure FDA0002421476040000035
is the average length of the data packet;
then according to the size E [ V ] of the bandwidth applied by ONU in the next periodi(k+1)]The ONUs are divided into 2 groups: high Load ONU (HighLoad ONU, HLONU) and Low Load ONU (Low Load ONU, LLONU), wherein the setONU in HLONU satisfies EVi(k+1)]＞WMAXThat is, the requested bandwidth of ONU is greater than the maximum authorized bandwidth, and the ONU in the set LLONU satisfies E [ V ]i(k+1)]≤WMAXThat is, the authorized bandwidth of the ONU is less than or equal to the maximum authorized bandwidth; when in use
Figure FDA0002421476040000036
And is
Figure FDA0002421476040000037
When it is, all ONU are in low load state and satisfy EVi(k+1)]≤WMAXMean value of polling period
Figure FDA0002421476040000038
When in use
Figure FDA0002421476040000039
And is
Figure FDA00024214760400000310
Mean of time, polling period
Figure FDA00024214760400000311
When in use
Figure FDA00024214760400000312
And is
Figure FDA00024214760400000313
When it is time, i.e. all ONUs are in a high load state and satisfy evi(k+1)]＞WMAXMean value of the polling period E [ T ]cycle]＝K(WMAX+Tg) Wherein T isgAnd K is the number of the ONU in the network.
5. A method of parallel path forwarding with redundant coding in WOBAN according to claim 3, characterized in that: the above-mentioned
Figure FDA00024214760400000314
Satisfies the following conditions: when ONUiWhen the element belongs to LLONU, namely ONU belongs to low-load ONU, mean value of authorized bandwidth
Figure FDA00024214760400000315
When ONUiWhen belonging to HLONU, namely ONU belongs to high-load ONU, mean value of authorized bandwidth
Figure FDA00024214760400000316
6. The method of parallel path forwarding with redundant coding in WOBAN according to claim 1, characterized in that: the redundant coding and the transmission to the destination node through the parallel path are specifically: grouping data packets to be sent by a source node according to M data packets in each group, performing redundant coding on the data packets in each group to generate M coded data packets, and then transmitting the coded data packets to a destination node through N parallel paths according to a flow distribution scheme; the destination node receives m linearly independent coded packets from the N parallel paths, decodes and recovers m original data packets; when any one parallel path fails, according to the coding scheme, the destination node receives at least m linearly independent coded packets from other N-1 parallel paths.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102571583A (en) * 2012-01-11 2012-07-11 浙江工业大学 Quality of service (QoS) aware self-adaptive bandwidth distribution system for wireless-optical broadband access networks (WOBAN) and self-adaptive bandwidth distribution method
CN103338471A (en) * 2013-06-27 2013-10-02 南京邮电大学 Service quality index evaluating method for wireless multi-hop network based on model
CN105515880A (en) * 2016-01-25 2016-04-20 重庆邮电大学 Token bucket traffic shaping method suitable for fusion network
JP2017028573A (en) * 2015-07-24 2017-02-02 パナソニックＩｐマネジメント株式会社 Retransmission control system and retransmission control method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102571583A (en) * 2012-01-11 2012-07-11 浙江工业大学 Quality of service (QoS) aware self-adaptive bandwidth distribution system for wireless-optical broadband access networks (WOBAN) and self-adaptive bandwidth distribution method
CN103338471A (en) * 2013-06-27 2013-10-02 南京邮电大学 Service quality index evaluating method for wireless multi-hop network based on model
JP2017028573A (en) * 2015-07-24 2017-02-02 パナソニックＩｐマネジメント株式会社 Retransmission control system and retransmission control method
CN105515880A (en) * 2016-01-25 2016-04-20 重庆邮电大学 Token bucket traffic shaping method suitable for fusion network

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
《WOBAN中基于令牌桶算法的自适应流量整形策略》;王汝言等;《电子与信息学报》;20170630;第39卷(第6期);全文 *

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