Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
  • H04W72/543—Allocation or scheduling criteria for wireless resources based on quality criteria based on requested quality, e.g. QoS
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L47/00—Traffic control in data switching networks
  • H04L47/10—Flow control; Congestion control
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L47/00—Traffic control in data switching networks
  • H04L47/10—Flow control; Congestion control
  • H04L47/24—Traffic characterised by specific attributes, e.g. priority or QoS
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L47/00—Traffic control in data switching networks
  • H04L47/10—Flow control; Congestion control
  • H04L47/32—Flow control; Congestion control by discarding or delaying data units, e.g. packets or frames
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/04—Wireless resource allocation
  • H04W72/044—Wireless resource allocation based on the type of the allocated resource
  • H04W72/0446—Resources in time domain, e.g. slots or frames
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/21—Control channels or signalling for resource management in the uplink direction of a wireless link, i.e. towards the network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/56—Allocation or scheduling criteria for wireless resources based on priority criteria
  • H04W72/566—Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient
  • H04W72/569—Allocation or scheduling criteria for wireless resources based on priority criteria of the information or information source or recipient of the traffic information
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W84/00—Network topologies
  • H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/08—Access point devices

Definitions

• the invention relates to a method and a resource allocation system. It applies in a communications network, particularly to communications in a radio network.
• the present invention finds its application in the field of radio networks operating on the principle of time division multiple access or "TDMA” (abbreviated Anglo-Saxon Time Division Multiple Access).
• TDMA time division multiple access
• frequency division multiplexing Frequency-Division Multiple Access or FDMA
• FDMA Frequency-Division Multiple Access
• TDMA time division multiple access
• a station or a node of the network plays the role of coordinator of the network by assigning the transmission times to different users or services according to their needs.
• This node can be called central node, master node, 0 "scheduler” or "cluster head” in English.
• each network node can be associated with a user or service.
• Ad hoc networks have the advantage of allowing high-speed transfers and the possibility of interconnection with existing structures. Implementing this type of network requires very precise and fair allocation management between users or services. Moreover, in such a network, the data to be transmitted do not all have the same needs.
• the voice "expires" quickly (around 250ms) and therefore the transmission delays must be minimized.
• the loss of some packets of this type of data does not significantly deteriorate the quality of transmission.
• the background traffic class which corresponds to secondary traffic with no real-time constraints, such as e-mail
• the data may be subject to deadlines, but it is imperative that all the packets be transmitted.
• QoS quality of service
• the needs expressed by the nodes can be related to the quality of service (QoS) of the associated service.
• Quality of service is specified by QoS parameters expressing characteristics intended for data transfer such as throughput, transit time, accuracy, and reliability.
• Classes can be based on a number of parameters such as priority, interface or original program;
• US Patent 2003/0198204 discloses a method and a system for allocating resources for the transmission of data subject to data constraints.
• Quality of Service QoS
• This system makes it possible to order the traffic by basing itself, initially, on static allocation parameters and then, by adapting this order thanks to compensation coefficients calculated according to the flow, waiting time in the queue waiting and priority.
• node or "station” is understood to mean any entity of the network implemented in hardware or software that may be the entry point or the exit point of an exchange or transmission of data or data. information between stations.
• a request characterizes a resource requirement, for example, a transmission slot ("slot in English"), associated with an application or a service class expressed by a node of a network with a mechanism allocation (the scheduler).
• a need may include an end-to-end QoS specification.
• the invention relates to a method for allocating resources in a communication network comprising a plurality of nodes adapted to transmit and receive data and a central node adapted to allocate resources, characterized in that it comprises at least the following steps: least one node sends one or more requests R nq t to the central node, each request R nq t being associated with a need q-,; the central node assigns a lifetime ⁇ t qi to each request
• each request R nq t is ordered in a queue as a function of the lifetime ⁇ tqi and the time of reception t R of the request, - the m first queries R nq t in the queue are retrieved for m available transmission times,
• the distribution of the transmission instants is recorded in a signaling flag and then transmitted from the scheduler to the nodes.
• the lifetime can be attributed to a request according to the application associated with the request.
• queries associated with urgent or important applications can be placed at the beginning of the queue.
• the lifetime can be attributed to a request based on a quality of service (QoS) associated with the request.
• QoS quality of service
• the lifetime can be attributed according to the temporal constraints of the application associated with the request or according to the time allowed for the application. transfer of the data associated with the request. This makes it possible to satisfy the most urgent requests and to provide a scheduling that responds to the real urgency of the packets.
• the network is for example an ad hoc network.
• the lifetime assigned to a request can depend on the number of nodes of the network that will have to cross the data to be transmitted. This ensures end-to-end data transmission over a network.
• a TDMA protocol can be used.
• the resources to be allocated can be the moments of transmission.
• queries are ordered in the queue according to the quality of service of the requests, an expiry time for a request being defined starting from the lifetime allocated to the request and the instant of receipt of the request.
• the method may include a step of discriminating between perishable queries and non-perishable queries.
• the method may, for example, further include a step of checking whether the requests are out of date, and eliminating the out-of-date request (s) from the queue. This allows the management of out-of-date data and thus respond to time constraints imposed by the services associated with the requests.
• Query verification can, for example, consist of comparing the expiry time of each request with the current instant and in the case where the expiry time of a request is less than the current instant. , the query is eliminated.
• each request is given an output lifetime and an output expiration time, defined from the life time at the output of the request, is compared with the instant of reception. of the query, with the current moment. In the case where the expiry time at the output of a request is less than the instant in progress, the request is eliminated.
• the network is for example a radio network.
• the lifetime assigned to a request can be adjusted based on the priority or time constraints associated with the request. This makes it possible to provide these requests with a competitive advantage in the access to the resource since they will be systematically preferred in the ranking in the queue.
• the invention also relates to a resource allocation system in a communication network comprising a plurality of nodes adapted to transmit and receive data and a central node adapted to allocate resources, characterized in that several nodes are equipped with a suitable processor. to: send one or more requests R nqt to the central node, each request R nq t being associated with a need q u and that the central node is equipped with a processor adapted to:
• the method and the resource allocation system according to the invention have the following advantages in particular: they make it possible to optimize the allocation of resources; they allow an allocation that is equitable between the nodes of a network; they make it possible to satisfy the priorities of the services associated with the nodes; they provide service guarantees in terms of speed and delay, whether point-to-point or end-to-end transfers; and - they make it possible to take into account the temporal constraints of the data to be transmitted and to guarantee a scheduling according to the real urgency of the data.
• the data are not interlaced by priority or flow but by real time constraints, and therefore by their real urgency. This interleaving is dependent on the data and not the flows, and therefore naturally adapts to the "burst" and non-deterministic nature of traffic such as voice, since it acts packet by packet.
• FIG. 1 shows an example of an ad hoc network with several nodes and a central node
• FIGS. 2A to 2C illustrate exchanges of data in the network of FIG. 1
• Figure 3 details the steps of the method according to one embodiment of the invention
• Figures 4A to E illustrate the method detailed in Figure 3
• FIG. 5 illustrates a data control step according to a variant of the invention
• FIG. 6 illustrates a data control step according to another variant of the invention.
• Figure 1 schematizes an example of an ad hoc network 1 operating on the principle of TDMA (multiple access by time division).
• the network 1 comprises a central node 2 and a plurality of nodes 3 connected to each other and to the central node 2 by communication links.
• Each node 3 is equipped with transmission / reception means and is associated with a service or a user.
• the central node 2 is also equipped with transmission / reception means and plays the role of coordinator or "scheduler" of the network by assigning the transmission instants to the nodes 3 according to their needs q.
• the need q may correspond to a quality of service.
• Nodes 3 may be mobile or non-mobile, for example, microcomputers, cordless telephones, digital television sets.
• the communication links can be either wired links or wireless links, for example, radio links.
• FIGS. 2A to 2C generally illustrate the exchanges of data in the network of FIG. 1.
• each node 3 sends at least one request, in the form of a data packet containing requests for the transmission instants, to the scheduler 2.
• a request corresponds to a data packet which contains a request for a moment or moments of transmission for a given node 3.
• Transmission time requirements are specified in a two-dimensional space (Time and Import, Quality of Service) from the applications associated with the nodes via a system known per se to specify the characteristics of a data stream, such as the use of the TOS "type of service" field of the IP packet header, the interpretation of the TCP / UDP header port that indicates the corresponding application or the use of multiple queues. From the requests received, the scheduler 2 determines the distribution of the times of transmission as will be explained below.
• the scheduler 2 transmits to the nodes 3, the distribution of transmission times that has been defined, as shown in Figure 2B.
• Nodes 3 use the transmission times assigned to them to transmit data packets to their recipient as shown in Figure 2C.
• FIGS. 3, 4A to 4C there is illustrated an example of the method for allocating transmission times for the various nodes. This process comprises the following steps:
• the scheduler 2 receives requests for resources or requests R nq t emitted by the nodes 3 where n represents the node requesting the resource, q the quality of service (QoS) associated with this request R nqt and M instant of reception of the request R nqt by the scheduler 2.
• FIG. 4A illustrates a first series of requests, Ri3o, Ri2o, R120 R100, R23o, R23o, R220 and R210 of two nodes N1 and N2 of the network, the requests being ranked according to quality of service qO to q3.
• the scheduler 2 allocates a lifetime ⁇ t q j to each request R nq t, depending on the quality of service qi associated with the request R nq t.
• the lifetime ⁇ t qi allocated to each request R nq t is chosen, for example, according to the temporal constraints of the application associated with the request.
• FIG. 4A illustrates the allocation of the lifetime ⁇ t qi to the first set of requests received by the scheduler at a time TO.
• FIGS. 4B and 4C illustrate the allocation of the lifetimes associated with a second series of requests Rm, R231 R221, R201 and a third series of requests. requests Ri32, Ri22, R232 R212, R202, respectively received by the scheduler at times T1 and T2.
• a third step 33a, 33b the scheduler 2 retrieves the requests R nqt starting from the most pressed to the least in a hurry. It then orders the requests R nq t in a queue by respecting the times of expiration of the requests as represented in FIG. 4D.
• the expiration time for a request R nq t is defined by t + At q ⁇ .
• the qualities of services q the highest are then privileged and placed before, when scheduling in the queue when the instants of expirations t + ⁇ t q ⁇ requests are equal.
• the method thus provides a queue where high priority queries are preferred, giving a satisfactory order of real urgency for queries.
• a fourth step 34a and 34b it is verified that the requests R nq t in the queue are not out of date.
• This control step consists in comparing the current instant Tc with the expiry time t + ⁇ t q ⁇ of the request R nq t. If the expiry time t + ⁇ t q ⁇ of the request R nq t is less than the current instant Tc, the request R nq t is eliminated from the queue as represented in FIG. 4E.
• the first m requests R nqt in the queue are retrieved for m transmission times available as shown in Figure 4E.
• a sixth step 36 the retrieved queries are ordered by node n as shown in FIG. 4E.
• a seventh step 37 the distribution of the transmission instants is recorded in a signaling flag and then transmitted from the scheduler to the nodes.
• the method does not include the fourth step 34a and 34b of controlling and eliminating out-of-date requests.
• the lifetime ⁇ t qi assigned to the requests it is possible to refine or adjust the lifetime ⁇ t qi assigned to the requests. For this purpose, it is possible to reduce or cancel a lifetime ⁇ t qi for applications with very high temporal or high priority constraints, for example voice. This makes it possible to provide these requests with a competitive advantage in the access to the resource since they will be systematically preferred in the ranking in the queue.
• the control step consists of defining output constraints distinct from the constraints imposed for the scheduling of the list. For this, we can assign a lifetime output ⁇ U for each request.
• the input lifetime ⁇ t qi aimed as appropriate, solely to benefit the requests of a given priority or QoS, does not always correspond to the actual acceptable constraints.
• the verification of out-of-date requests consists of comparing the expiration time in output, defined from the output life time and the instant of receipt of the request, with the current instant. Thus, requests with an exit expiration time lower than the current time will be eliminated from the queue.
• the method may further comprise a discrimination step between perishable requests and non-perishable requests.
• FIG. 5 illustrates a variant of the invention in which the method comprises a discrimination step 52 between perishable requests and non-perishable requests and a control step 53 where the perishable requests are then checked, according to one of the control methods described hereinabove. above, to check if they are out of date or not.
• Non-stale and non-perishable queries such as queries associated with e-mail, are kept in queue 54 for sending the allocation to the nodes.
• FIG. 6 illustrates another variant of the invention in which the method comprises a control step 63 in which the non-perishable requests are re-scaled in the queue 61 and the out-of-date requests are eliminated in the case where it is not possible. more minutes of transmission to allocate. This helps to manage queue congestion and ensure the highest quality of service requests.
• the step of controlling perishable and non-perishable requests may consist in allocating a dummy life to non-perishable requests. This lifetime is chosen, for example, according to the priority of the traffic, making it more or less competitive, but is not taken into account by the output control. Non-perishable requests are added to requests allocated according to the temporal urgency order without any verification of their possible expiry.
• the lifetime can be allocated to each request or refined according to one or more of the following criteria: the application associated with the request, the temporal constraints related to the application and / or the number of nodes of the network that the data will have to traverse.
• This method can be interfaced to a mechanism of "MAC” type “connected mode” or "RSVP type” network level sessions which is able to provide the urgency and importance characteristics of the data to be transmitted.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Quality & Reliability (AREA)
• Mobile Radio Communication Systems (AREA)
• Small-Scale Networks (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

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• 2006
  • 2006-03-27 FR FR0602649A patent/FR2899054B1/fr not_active Expired - Fee Related
• 2007
  • 2007-03-26 WO PCT/EP2007/052880 patent/WO2007110413A1/fr active Application Filing
  • 2007-03-26 US US12/294,466 patent/US20110047271A1/en not_active Abandoned
  • 2007-03-26 EP EP07727353A patent/EP1999905A1/de not_active Ceased
• 2008
  • 2008-09-25 IL IL194380A patent/IL194380A0/en unknown

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