METHOD AND SYSTEM FOR SIMULATION AND MANAGEMENT OF THE RESOURCES OF A MOBILE TELEPHONE NETWORK

• US 20070149186A1
• Filed: 11/14/2006
• Published: 06/28/2007
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Societe Francaise De Radiotelephone SA (Altice Europe NV)
• Original Assignee: Societe Francaise De Radiotelephone SA (Altice Europe NV)
• Inventors: Chrabieh, Rabih, Fattouch, Imad, Barbosa da Torre, Serge
• Granted Patent: US 7,308,268 B2
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A method and a system for simulating and optimising the operating resources available in a coverage area of a mobile telephone network implemented by processing resources of at least one resource optimisation system and, can include definition, by an event-management module of the optimisation system, of a variation, called a perturbation, of at least one transmission of packets required within the network, from at least one statistical distribution map, selection of a set of cells determining a simulated zone, by means of an operating-resource control module, and then use of a routing algorithm to determine a routing path in the simulated zone, and to successively optimise the resources of the servers, definition by the event-management module, of data that represent at least one parameter relating to the transmission of the packets within each of the cells in the simulated zone, from amongst at least parameters of time-multiplexing of the packet, code-multiplexing of the packet, and the power required.

Claims

1. A method for simulating and optimising the operating resources available in a coverage area of a mobile telephone network consisting of a set of zones of influence, called cells, of a plurality of transmitters/receivers, called servers, whose operating resources depend on the transmission of data sets, called packets, required by at least one communicating mobile terminal, called the applicant terminal, present in their zone of influence, wherein, firstly, it is implemented by processing resources of at least one resource optimisation system and, secondly, it includes the following stages:

definition, by an event-management module of the optimisation system, of a variation, called a perturbation, of at least one transmission of packets required within the network, where this perturbation is determined from at least one statistical distribution map held in storage resources of the optimisation system and including data that represent the data packet transmissions of a plurality of mobile terminals present in a given geographical zone during a given time-slice,

selection of a set of cells that includes at least the cell in which the perturbation occurs, and that defines a simulated zone within the distribution map by means of an operating-resource control module, and then use of a routing algorithm, ran by the operational control module, to determine a routing path of the simulated zone, and to successively optimise the resources of the servers covering the successive cells on the routing path,

definition, by the event-management module of data that represent at least one parameter relating to the transmission of the packets within each of the cells in the simulated zone, from amongst at least parameters of time-multiplexing of the packet, code-multiplexing of the packet, and power required.

2. A method according to claim 1, wherein the stage for definition of at least one parameter from the time-multiplexing of the packet, the code-multiplexing of the packet and the power required, by the event-management module, includes at least one of the following stages:

determination of time-slices, called time-slots or subframes, allowing multiplexing in time of the packets in the course of at least one frame of transmission,

determination of codes allowing multiplexing by codes of the packets in the course of at least one frame of transmission,

determination of the power allocated to each of the packets in the course of at least one frame of transmission,

determination of a type of time-slot used for the transmission of packets according to the different service types provided by the servers, where this type of time-slot is either a “

full-rate”

time-slot, or a “

half-rate”

time-slot, or a “

packet-only”

time-slot, or a “

mixed”

packet and circuit time-slot.

3. A method according to claim 2, wherein the stage of determination of codes includes a stage for determining the number of codes attributed to each of the packets and a stage for determining the type of modulation used for these codes.

4. A method according to claim 2, wherein the stages for determining the time-slots, for determining the codes and for determining the power, are implemented, for each of the packets, by a packet scheduling module used to determine the codes and the time-slots by means of which each of the packets will be transmitted in the course of at least one frame of transmission, as well as the power allocated to each of the packets.

5. A method according to claim 2, wherein the stage for determining the time-slots is replaced by a stage for the evaluation of a portion of time occupied by the transmission of each of the packets, with no determination of time-slots but considering only the total time during which each of the packets is transmitted.

6. A method according to claim 5, wherein the stage for the evaluation of the time portion occupied by the transmission of each of the packets is based upon an approximation that consists of a calculation of the average power used during the time for the transmission of each of the packets, and of a smoothing of the power over the total time portion occupied by each of the packets, through the use, by the event-management module, of at least one algorithm from amongst the following algorithms for time distribution of the packets:

an individual transmission algorithm, according to which a single packet is transmitted in the course of each of the time-slot, then using all of the power available during this time-slot,

a grouped transmission algorithm, according to which a plurality of packets is transmitted during a given time portion, by multiplexing by codes, these packets each using a portion of the total available power.

7. A method according to claim 6, wherein it includes a stage for determination of the interference perceived by each of the servers responsible for the transmission of each of the packets during the time portion in the course of which they are transmitted, where this stage is implemented by means of the stage for determination of the power allocated to each of the packets in the course of at least one frame of transmission and by use of the algorithms for time distribution of the packets by the event-management module, with this determination of the perceived interference allowing the calculation of a signal-to-noise ratio for each of the packets.

8. A method according to claim 6, wherein the use of the grouped transmission algorithm by the event-management module is accompanied by a stage for the allocation of different time portions to the different packets transmitted in the course of a frame of transmission, by the use of an algorithm from amongst the following algorithms for the allocation of a time portion:

A “

fair-share”

algorithm, according to which the time portion allocated to each of the packets is a function of the total time of the frame of transmission divided by the number of packets to be transmitted,

a maximising algorithm, according to which the time portion allocated to each of the packets is a function of a value of at least one parameter relating to the transmission of the packet divided by the sum of the values of this parameter or these parameters for the other packets.

9. A method according to claim 1, wherein it includes a preliminary stage for the establishment of at least one distribution map including data that represent the traffic and the location of servers in the coverage area of the network, where these data representing the traffic are quantitative and qualitative measurements of the location of a plurality of mobile terminals and servers operating in the coverage area of the network and of the data packet transmissions effected in the course of time-slices chosen for their statistical significance, where the data corresponding to these measurements are held in the storage resources of the optimisation system.

10. A method according to claim 1, wherein it includes a stage for the establishment of at least one distribution map including data that represent the traffic and the location of servers in the coverage area of the network, with the data that represent the traffic being generated by the event-management module and representing, firstly, the location of a plurality of mobile terminals distributed randomly in the coverage area of the network at a predetermined density and, secondly, the data packet transmissions required by these terminals assigned randomly to the different terminals present in the network, from random laws stored in the storage resources of the optimisation system.

11. A method according to claim 1, wherein it includes a stage for the recording, in the storage resources of the optimisation system, of at least one routing algorithm allowing the operating-resource control module to determine a routing path consisting of the selection of any cell in the simulated zone and then a plurality of iterations for the selection of a cell adjacent to the cell selected previously, until all the cells in the simulated relation to the first cell selected.

12. A method according to claim 1, wherein it includes a stage for the recording, in the storage resources of the optimisation system, of at least one routing algorithm determining concentric circles centred on the cell in which the perturbation occurs and allowing the operating-resource control module to determine a routing path consisting of successive selections of the cells in the simulated zone through which these concentric circles pass in ascending order of the distance of these cells in relation to the first cell selected.

13. A method according to claim 1, wherein the stage for the use of the routing algorithm by the operating-resource control module is accompanied by a stage for the creation of data that represent a grid for separation of the simulated zone into divisions, each including an index obtained from the coordinates of the cells, used to locate each of the divisions and to classify them in ascending order of their distance in relation to a central division.

14. A method according to claim 13, wherein the stage for the use, by the operating-resource control module, of a routing algorithm results in the determination of concentric circles centred on the cell in which the perturbation occurs, and is accompanied by a stage for determining a routing path that includes at least one vector indicating the path to be followed from one division to the next within the simulated zone, in order to allow successive selections of the divisions of the simulated zone through which these concentric circles pass, and successive selections of the cells contained in each of these divisions in ascending order of their distance in relation to a central division.

15. A method according to claim 13, wherein the data that represent the grid for separation of the simulated zone into divisions includes data that represent the coordinates of the division allowing the operating-resource control module to determine the location of the cells, as well as the divisions and neighbouring cells.

16. A method according to claim 1, wherein the stage for the use of the routing algorithm by the operating-resource control module is accompanied by a stage for the creation, for each cell in the simulated zone, of data that represent the neighbouring cells in the simulated zone, so as to determine a routing path for each of the cells, one after the other.

17. A method according to claim 16, wherein the routing path in the cells within a division is determined in a random manner.

18. A method according to claim 1, wherein the stage for the use of the routing algorithm by the operating-resource control module is accompanied by the creation, for each cell in the simulated zone, of data that represent a marker indicating the cells already visited during the passage through the simulated zone by the operating-resource control module.

19. A method according to claim 1, wherein the stage for definition of the perturbation consists of the random and automatic selection of a communicating mobile terminal in a distribution map extracted from the storage resources of the optimisation system and in that the stage for the selection of a set of cells determining a simulated zone within the distribution map consists of selecting at least one server whose cell can cover the location at which this terminal is located in the distribution map.

20. A method according to claim 1, wherein the stages for definition of the perturbation and for selection of a set of cells determining a simulated zone within the distribution map, consist of the selection of a communicating mobile terminal present in the coverage area of the network and of at least the servers whose cells can cover the position at which this terminal is located in the distribution map, from information entered and recorded by a user of the resource optimisation system, by means of interactive resources between the user and the resource optimisation system.

21. A method according to claim 1, wherein, firstly, the stage for definition of the perturbation is implemented during a request for the transmission of a data packet by an applicant mobile terminal present in the coverage area of an operational mobile telephone network, and consists of the location of the communicating mobile applicant terminal in the coverage area of the network and identification of the type of transmission that it requires and, secondly, the stage for the selection of a set of cells at least one server whose cell can cover the location at which this terminal is located in the distribution map.

22. A method according to claim 1, wherein the stage for definition of data that represent at least one parameter relating to the transmission of the packets is implemented by the resource optimisation system, either in a random and automatic manner, or from information entered and recorded by a user of the resource optimisation system, or from transmission parameters required by a communicating mobile terminal during a transmission request.

23. A method according to claim 1, wherein the stage for definition of the perturbation by the event-management module includes at least one of the following stages:

a request for a new transmission, handled by an event control module,

the ending of a transmission, handled by the event control module,

the expiry of a transmission timeout, handled by the event control module,

simulation of the mobility of the communicating mobile terminal responsible for the perturbation, handled by a mobility simulation module,

changing of the transmissions of current packets, handled by a packet-scheduling module.

24. A method according to claim 23, wherein the stage for simulating the mobility of the communicating mobile terminal responsible for the perturbation consists of one of the following stages:

modelling a speed of movement of the communicating mobile terminal by changing the required signal-to-noise ratio, which allows modelling of the level of losses or of the gain due to variations in the strength of the signal perceived by the mobile communicating terminals, or

changing the location of the communicating mobile terminal in the distribution map by selection of a neighbouring communicating mobile terminal in the map.

25. A method according to claim 1, wherein it includes a stage for controlling the traffic between the servers of the simulated zone and the mobile terminals present in the simulated zone, implemented by a traffic control module of the optimisation system determining, for each of the current transmissions, sessions for the transmission of packets, the support transmission path, called bearer and the transmission channels of these packets, this stage being accompanied by at least one of the stages for determination of the multiplexing and power parameters.

26. A method according to claim 25, wherein the stage for the control of traffic by the traffic control module of the optimisation system consists of determining a plurality of parameters relating to the services and to the resources used by the mobile terminals present in the simulated zone, where this determination results from at least one stage for the extraction of data that represent these parameters, from a distribution map, and of a possible stage for the creation of data that represent these parameters, from information entered by a user of the optimisation system, so as to allow at

determination of sessions corresponding to transmissions of data packets between the servers of the simulated zone and each of the mobile terminals present, with determination of the packets transiting in the course of the sessions;

determination of at least one bearer associated with each of the transmissions of each of the mobile terminals, with determination of at least one parameter from the parameters relating to the type of the bearer, the throughput (data rate) of the bearer, the quality of the signal required, the transmission channels used for each of the cells, and the range of authorised power levels.

27. A method according to claim 2, wherein it includes a stage for controlling the acceptability of the transmission of this packet, by a call admission control module of the resource optimisation system performing a determination of a set, called the active set, of cells available within the simulated zone, by verification of the availability, in the simulated zone, of at least one parameter from amongst the power, the channels and the parameters for multiplexing by codes and by time or the type of time-slots employed, and then classification of the servers of the active set according to their contribution (Ec/lo) to the total power of the signals exchanged with the communicating mobile terminal, with the call admission control module then making a decision, according to the traffic, about the acceptability of the transmission of this packet via at least one support transmission path, called the bearer, and at least one channel for transmission of the packet via at least one server covering one of the cells in the active set.

28. A method according to claim 2, wherein it includes an operating-resource control stage, implemented by the operating-resource control module of the optimisation system during a variation in the number of packets transmitted within the simulated zone, and consisting of verifying at least one parameter used by the mobile terminals in the cells constituting the simulated zone from amongst at least the power and the parameters for multiplexing by codes and by time or the type of time-slots employed, and then adjusting this parameter or these parameters for at least one server covering at least one cell in the simulated zone.

29. A method according to claim 2, wherein it includes a load control stage for each of the cells in the simulated zone, implemented by a load control module of the optimisation system, in the event of excessive use of the resources of at least one server of the simulated zone, consisting of the use of at least one load control algorithm from amongst at least one constant-power load control algorithm and at least one variable-power load control algorithm held in the storage resources of the optimisation system and including the following stages:

verification of the resources used, at the level of at least one parameter from amongst the power, the channels used and the multiplexing parameter by codes and by the time or the type of time-slots employed, in the cells constituting the simulated zone, to select at least one server whose resources are being used excessively;

selection of at least one packet from amongst the packets, called excess packets, using the maximum of power or using a maximum throughput (data speed rate) on the transmission channels between the mobile terminals present and the server whose resources are being used excessively;

a decision between refusal of the selected excess packet and downgrading of the transmission parameters of the selected excess packet.

30. A method according to claim 29, wherein the decision stage between refusal of the selected excess packet and downgrading of the transmission parameters of the selected excess packet, during the load control stage by the load control module, depends on the load control algorithm used and includes the following stages:

verification of the switching method, by circuit or by packet, used by the selected excess packet;

verification of the parameters of the bearer used by the selected excess packet;

verification of a list of servers of the active set classified according to their contribution (Ec/lo) to the total power of the signals exchanged with the communicating mobile terminal, to determine whether there exists another server capable of allowing transmission of the selected excess packet, when the power of the signal supplied by a server is insufficient.

31. A method according to claim 29, wherein the decision stage between refusal of the selected excess packet and downgrading of the transmission parameters of the selected excess packet, during the stage to control the loading, by the use of at least one constant-power load control algorithm, consists of holding constant the power initially allocated to the packets during the whole period of their transmission, and downgrading of the parameters for multiplexing by codes in accordance with the instantaneous signal-to-noise ratio, so as to reduce the throughput of the selected excess packet while keeping the signal-to-noise ratio above its required value, or in a refusal of the selected excessive packet if the required signal-to-noise ratio cannot be maintained.

32. A method according to claim 29, wherein the decision stage between refusal of the selected excess packet and downgrading of the transmission parameters of the selected excess packet, during the load control stage, by the use of at least one variable-power load control algorithm, consists:

either of downgrading of both the code-type multiplexing parameters initially allocated to the packets and the power parameters, in accordance with the instantaneous signal-to-noise ratio, so as to reduce the throughput of the selected excess packet while keeping the signal-to-noise ratio above its required value,

or, when the power cannot be regulated, of downgrading only the parameters for multiplexing by codes in accordance with the instantaneous signal-to-noise ratio, so as to reduce the throughput of the selected excess packet while keeping the signal-to-noise ratio above its required value,

or of refusal of the selected excessive packet if the required signal-to-noise ratio cannot be maintained.

33. A method according to claim 2, wherein it includes a stage to control the load of each of the cells in the simulated zone, implemented by a load control module of the optimisation system, by the use of at least one time-slot load control algorithm, either when a mixed time-slot is used only for the transmission of a circuit-switched packet while it normally allows either the transmission of both packet-switched packets and circuit-switched packets, or when a packet is abandoned, where this load control stage consists of allocating fairly shared resources to all of the packets in the process of transmission, according to the capacity of the communicating mobile terminals responsible for these transmissions, and possible refusal of the most recent packet if the number of packets being transmitted exceeds a predetermined value.

34. A method according to claim 2, wherein it includes a stage to control the load of each of the cells in the simulated zone, implemented by a load control module of the optimisation system, during a reduction in the use of the resources of at least one server of the simulated zone, consisting of the use of at least one load control algorithm held in the storage resources of the optimisation system, and including the following stages:

verification of the resources used, at the level of at least one parameter from amongst the power, the channels used and the parameters for multiplexing by codes and by time or the type of time-slots employed, in the simulated zone, to detect at least one server that has unused resources;

selection of at least one packet from amongst the packets, called disadvantaged packets, using a minimum throughput on the transmission channels of the server that has under-used resources;

upgrading of the transmission parameters of the selected disadvantaged packet, by increasing the value of at least one parameter of the bearer used by this selected disadvantaged packet until a satisfactory operating level is attained, as determined in the load control algorithm.

35. A method according to claim 34, wherein the stage to control the loading of each of the cells in the simulated zone is associated with a stage for the detection of any oscillations between two values of at least one parameter of the bearer used by a packet in the process of reconfiguration by the load control module and, where appropriate, attributing the minimum value attained by the oscillation to this parameter.

36. A method according to claim 29, wherein the stage to control the load of each of the cells in the simulated zone is implemented by activation of the load control module by the operating-resource control module, in order to improve the quality of the transmission of the packets of the different mobile terminals present in at least one cell in which the perturbation occurs, as determined by the event-management module.

37. A method according to claim 29, wherein the stage to control the load of each of the cells in the simulated zone is implemented by automatic activation of the load control module, when the power required by a channel for the transmission of a packet increases beyond an authorised maximum, and consists of automatic selection of this packet as an excess packet and then downgrading of the transmission parameters of this selected excess packet.

38. A method according to claim 27, wherein the stage for controlling the acceptability of the transmission of the packet of the applicant mobile terminal consists of the use, by the call admission control module, of at least one admission control algorithm from amongst at least one coding-determined admission control algorithm and at least one time-slot-determined admission control algorithm, held in the storage resources of the optimisation system and includes the following stages:

determination of the active set of cells available for the transmission of the packet of the applicant terminal, by measurement and classification of a plurality of servers of the simulated zone, whose number depends on the location and the type of the applicant terminal;

verification of the availability of resources, for each of the cells in the simulated zone, at the level of at least one parameter from amongst the power, the channels and the parameters for multiplexing by codes and by time or the type of time-slots employed, and then classification of the servers of the active set according to their contribution (Ec/lo) to the total power of the signals exchanged with the communicating mobile terminal;

determination of the power required by the transmission channels of the packet for each of the cells, and verification that this power required by each of the cells does not exceed the maximum power of the bearer determined for the transmission of the packet of the applicant terminal;

verification that the status of at least one of the cells allows the acceptance of transmissions of data by a new communicating mobile terminal.

39. A method according to claim 5, wherein the use, by the call admission control module, of at least one coding-determined admission control algorithm results in a decision, according to the traffic, on the acceptability of the transmission of the packet of the applicant mobile terminal, where this decision consists of one of the following stages:

acceptance of the transmission of the packet of the applicant terminal, when the conditions necessary for the acceptance of a new transmission have been satisfied, after selection of a server for the transmission of the packet and selection of the bearer to be used for this transmission, with allocation of the highest possible initial coding parameters in the server, according to the number of channels available and the power required, and then allocation of an initial time portion;

refusal of the transmission of the packet of the applicant mobile terminal by the server, when the number of channels available is insufficient or when the power required is too high, even for the lowest coding parameters available on the server.

40. A method according to claim 38, wherein the use, by the call admission control module, of at least one time-slot-determined admission control algorithm, results in a decision, according to the traffic, on the acceptability of the transmission of the packet of the applicant mobile terminal, where this decision consists of one of the following stages when the packet is using circuit-switching:

acceptance of the transmission of the packet of the applicant terminal, when the conditions necessary for the acceptance of a new transmission have been satisfied, after selection of a server for the transmission of the packet and selection of the bearer to be used for this transmission, with allocation of a time-slot of the full-rate type if such a time-slot is available on the server or allocation of a time-slot of the half-rate type if the packet is a half-rate call;

reconfiguration by the use of at least one reconfiguration algorithm of the transmission of data when the conditions necessary for the acceptance of a new transmission have not been satisfied and the storage resources of the optimisation system are holding at least one reconfiguration algorithm, in order to allow a modification of the data relating to the bearer, and to increase the chances of acceptance of the transmission;

refusal of the transmission of the packet of the applicant mobile terminal, when the conditions necessary for acceptance have not been satisfied and the storage resources of the optimisation system are storing no reconfiguration algorithm, or the traffic within the simulated zone does not allow effective reconfiguration of the transmission of the packet.

41. A method according to claim 40, wherein the stage for reconfiguration by the use of at least one algorithm for reconfiguration of the transmission of the packet, implemented by the call admission control module when the conditions necessary for the acceptance of a new transmission, determined by the time-slot-determined admission control algorithm, have not been satisfied, and the storage resources of the optimisation system are holding at least one reconfiguration algorithm, results in:

either a search for a call to which a time-slot of the full-rate type is allocated, and then, where appropriate, allocation of a slice of the half-rate type to this call and allocation to the new transmission of the time-slot of the full-rate type thus freed;

or a search for a time-slot of the mixed type, and, where appropriate, allocation of this mixed time-slot to the new transmission, and then adaptation of this mixed time-slot to the new circuit-switched transmission.

42. A method according to claim 38, wherein the use, by the call admission control module, of at least one time-slot-determined admission control algorithm results in a decision, according to the traffic, on the acceptability of the transmission of the packet of the applicant mobile terminal, where this decision consists of one of the following stages when the packet is using packet-switching:

the search for a transmission block consisting of a combination of time-slots of the packet-only type and time-slots of the mixed type in a bearer and then, where appropriate, acceptance of the transmission of the packet of the applicant terminal and allocation of this block to the new transmission;

the refusal of the transmission of the packet of the applicant mobile terminal, when no transmission block is available for acceptance of the new transmission.

43. A method according to claim 1, wherein it is implemented by an application for the simulation and optimisation of resources, executed on the processing resources of the resource optimisation system and controlling the processing resources and the interoperability of the traffic control module, of the admission control module, of the load control module and of the operating-resource control module, and accessing the storage resources of the optimisation system in order to load the data necessary for the different modules, where the process includes a stage for installation of the application on the optimisation system by the recording, in the storage resources of the optimisation system, of data allowing execution of the application on the processing resources of the optimisation system.

44. A method according to claim 43, wherein the stage for installation of the application on the optimisation system includes a stage for implementation of the optimisation application within a software environment supplied by a cell planning application executed on the processing resources of at least one server within the coverage area of the network, by the recording, in storage resources of the server, of data allowing execution of the application for optimisation of the resources within the cell planning application of the server which thus constitutes an optimisation system.

45. A method according to claim 1, wherein the stages for definition of the perturbation and selection of a simulated zone are accompanied by a stage for loading into a working memory, of the volatile or very fast access type, of the resource optimisation system, of at least certain data stored in the storage resources of the optimisation system.