Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W48/00—Access restriction; Network selection; Access point selection
  • H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
  • H04W48/12—Access restriction or access information delivery, e.g. discovery data delivery using downlink control channel
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W48/00—Access restriction; Network selection; Access point selection
  • H04W48/18—Selecting a network or a communication service

Definitions

• the field of the invention is that of digital radiocommunications.
• the invention relates to access to different services, for example the Internet, digital video, voice transmission and / or multimedia data at the rate, ..., for a user equipped with a radiocommunication terminal, when the user is located in a coverage area 10 common to several different technology networks.
• Such networks are for example of type:
• UMTS Universal Mobile Telecommunications Service
• GSM Global System for Mobile
• DVB-H Digital Video 20 Broadcasting - Handhelds
• portable digital television system for example
• WLAN Wireless Local Area Network
• WWAN Wireless Wide Area Network
• the invention relates to the optimization of the connection to one of these networks, called the secondary network, distinct from a so-called main network, to which the terminal connects by default, in standby mode.
• the main network implemented can, for example, be of UMTS type.
• a user of a terminal located in a coverage area common to a UMTS-type main network, and at least one secondary network, can access a service of the secondary network by first connecting to the network. primary, then to the secondary network.
• paging group also called “paging” group, or “paging” 12 (of the English “Paging Group"), when it is located in a cell of the UMTS network.
• the terminals 11, 112, 113 of a group of users 12 are in standby mode, that is to say in a mode where they are not in connected mode, but present and available for a communication in the cell of the UMTS network.
• These terminals are in particular listening for signals transmitted by a base station belonging to this cell. These signals are emitted on:
• BCH Broadcast CHannel
• PCH mobile search channel
• common transport channels corresponding to the physical layer of the communication protocol, in particular on CPICH channels (or “common pilot channel” of the English “Common Plot CHannel”).
• each user group 12 is associated with an indicator, called call indicator, carried by the physical channel PICH (of the English “Paging Indicator CHannel", for "call indicator channel”
• PICH of the English “Paging Indicator CHannel”
• This PICH channel periodically sends information to the PCH channel.
• FIG. 2 shows the structure of a radio frame on the PICH channel of the UMTS network.
• Such a PICH frame comprises 300 bits, and has a length of 10 ms. Of the 300 bits of a frame, 288 bits are used to carry the call indicators (also called "paging" indicators). The remaining 12 bits are not used and are not transmitted.
• call indicators are intended in particular for a group of users 12 to indicate that a message is intended for a user 11 of the group 12.
• this message (“Paging Typel”) is sent on the S-CCPCH (the "Secondary Common Control Physical Channel”) where the channel is located PCH to ask the user to establish a signaling connection with the main network, in a second step 22.
• the PCH channel carries a message including the user identifier (in English TMSI for "Temporary Mobile Station Identity”) and the cause of call (English “PagingCause”).
• the terminal 11 of the user concerned On receipt of this message, the terminal 11 of the user concerned starts the signaling connection establishment procedure, and switches from standby mode "idle" to a mode connected to the main network.
• the terminal checks the radio resources available on the main network (from the English RRC for "radio resource Control "), and allocate resources according to availability (allocation of the RAB, the English" Radio Access Bearer ").
• the terminal 11 while remaining in connected mode, is then redirected to another UMTS cell, during a cell reselection procedure, or to another network, during a transfer procedure 24, called "handover".
• handover a transfer procedure 24, called "handover"
• the terminal 11 is powered on.
• the MSC / VLR (mobile switching center / visitor location register) switch for "mobile service switch / visitor location recorder” then requests the broadcast of a "paging" message (including the identity temporary TMSI terminal), by the RNC (or “RNC radio network controller") in the various cells of the terminal location area 11.
• RNC radio network controller
• the identified terminal then establishes the RRC connection, the "Paging response" message is routed to the MSCAT - R.
• the terminal 11 is then authenticated and the required resources are allocated.
• connection technique presented allows a terminal to switch from a primary network to a secondary network providing a desired service.
• This technique implemented when the desired service is not supported by the main network, or when the main network does not have sufficient resources, has several disadvantages.
• a first disadvantage of this technique is that it requires the use of resources of the main network while the service requested by the user is not supported by the main network, but by a secondary network.
• a user requires a service, for example a digital video
• obtaining the video requires prior switching to connected mode with the main network, even if the Radio resources needed for this connection are not available in the main network, while they are available in the DVB network.
• an object of the invention is to provide a technique that allows a user to simply and efficiently access a secondary network, even when the main network resources are not available, and / or when a desired service by the user is not available on the main network.
• Another objective of the invention is to propose such a technique that simplifies and optimizes the mode changes from the standby mode to the connected mode, and vice versa, on the different networks.
• the invention also aims to provide such a technique does not require the addition of additional messages, for example relating to the requested service.
• an objective of the invention is to propose such a technique that makes it possible to optimize the allocation of radio resources, and does not require the allocation of additional resources for the allocation of the service.
• Yet another object of the invention is to implement such a technique simply, efficiently and inexpensively.
• a radiocommunication terminal to a communication network among at least two accessible communication networks, one of which first network, said main network, and at least one second network, said secondary network, the main network implementing at least one main communication channel and a signaling channel.
• the signaling channel carries service accessibility information in the secondary network (s).
• the terminal reads the service accessibility information, in a standby mode, and can connect directly to one of the secondary networks, without going into connected mode on said main network, if said accessibility information indicates that an audit connection secondary network is possible.
• accessibility information indicates that an audit connection secondary network is possible.
• the service accessibility information transmitted over the signaling channel makes it possible to indicate either that the service is available on the secondary network and that the resources necessary for the connection with the secondary network are available, or that the service is available. on the secondary network, without any information on the availability of resources.
• the invention is based on a completely new and inventive approach of connecting a terminal to a secondary communication network, not requiring to go into connected mode on the main network to then be able to switch to the secondary network. selected.
• the invention thus optimizes the allocation of radio resources, and allows a user to connect directly to a secondary network, even if the main network does not have available radio resources.
• a channel of the main communication network carries information concerning service accessibility, that is to say the existence of a service and / or the availability of the resources necessary for connection to different networks. (or services) that a user may wish to access. Based on this accessibility information, the terminal can therefore connect directly to the secondary network providing such a service, without going into connected mode on the main network.
• the main network implements two signaling channels: a paging channel comprising, among others, signaling notification data, in the form of messages belonging to a predetermined message list;
• a paging indicator channel returning to said paging channel, when signaling notification data is present for said terminal or for a group to which said terminal belongs, one of said messages indicating that service accessibility information is present for said terminal or for a group to which said terminal belongs.
• These two paging channels and paging indicators thus make it possible to identify a terminal present in a cell, belonging to a group of users, and to send it, to itself or to the group to which it belongs, a message concerning the information service accessibility, if the terminal (or the group to which it belongs) is affected by the message.
• this accessibility information is carried by the paging indicator channel.
• this paging indicator channel is organized into frames having, in each of the frames, a first portion carrying paging indicators and a second portion carrying the service accessibility information.
• the pagination indicators also called call indicators, are notably associated with a group of users present in a cell of the main network.
• connection method according to the invention is particularly remarkable in that it implements, in said terminal, the following steps:
• the terminal located in the common coverage area of the different networks in standby mode, stores the second part of the frame, including in particular the accessibility information, if one of the indicators of the indicator channel of pagination is the group of users to which the terminal belongs.
• the terminal will read the paging channel to see if a message is addressed to it. If this is the case, he can decode the message.
• the terminal can then switch to the secondary network, using the service accessibility information that the terminal has read on the paging indicator channel, and then stored .
• the terminal can thus go directly from the standby mode to the connected mode on the secondary network, presenting available resources, without going into connected mode on the main network.
• each of the frames of the paging indicators comprises 300 bits channel, of which 12 for the second portion.
• at least 3 of the 12 bits of the second part can be used to indicate the network type It is thus possible to "code" a GSM network with bits OO1 ', a UMTS network with bits'100', a DVB-H network with bits' 011 '...
• the remaining bits of the second part may in particular be used to define a carrier frequency of the secondary network, an identity of a communication cell of the secondary network, a type of service available on the secondary network or an available bandwidth information.
• the main network is a UMTS type network
• the paging channel is the PCH channel
• the paging indicator channel is the PICH channel.
• the second part of each frame of the paging indicator channel corresponds to the unused 12 bits of the PICH channel in the UMTS standard.
• the message indicating the presence of accessibility information corresponds to the "spare" part of the "PagingCause” message carried by said PCH channel.
• Secondary networks belong in particular to the group comprising networks of the type:
• WLAN wireless local area network
• WWAN wireless wide area network
• the invention also relates to a radiocommunication terminal implementing the connection method described above.
• the terminal comprises means for analyzing the accessibility information in standby mode in said main network, and connection means connected to one of said secondary networks, from said standby mode.
• the invention also relates to a radiocommunication system in a main network implementing said connection method described above.
• the system implements a step of insertion of the accessibility data in said signaling channel.
• FIGS. 1A, 1B, 1C and 2 already presented in relation to the prior art, show a connection technique to a secondary network such that specified in the UMTS standard;
• Figure 3 illustrates a common coverage area in a multiple network system;
• FIG. 4 presents a technique of connection to a secondary network according to the invention;
• FIG. 5 illustrates the structure of a radio frame on a PICH channel according to the invention for the exchanges between a terminal located in the common coverage area of FIG. 3 and a main network. 7.
• the general principle of the invention is based on a technique enabling a terminal to switch from a main network to a secondary network, the user being located in a coverage area common to these two networks, when the radio resources of the main network are not available, and / or when a service desired by the user is not available on the main network but available on a secondary network, by going directly to the secondary network.
• the invention proposes to analyze a paging indicator channel between the terminal and the main network, this channel including service accessibility information relating to the existence of a service and / or the availability of the resources needed for the connection.
• This information thus makes it possible to identify the secondary network to which the user must connect in order to benefit from the requested service, without having to switch to connected mode with the main network.
• the invention applies especially in the case where the user (or his terminal) 11:
• - is in the common multi-network coverage area; is implemented on a main network; and when the desired application (or service) can not be offered by the backbone.
• These networks are for example of the DVB, UMTS, WLAN / WWAN or GSM / GPRS / EDGE type.
• the terminal 11 is then registered in a group of users of the main network. Such a user group is already described, in connection with Figures IA, IB and IC.
• this terminal 11 is listening for signals transmitted by a base station of the main network, and in particular listening to a paging channel and a paging indicator channel.
• This paging indicator channel includes paging indicators and accessibility information, and can be organized into successive frames.
• This service accessibility information specifies in particular the radio resource available on the different secondary networks.
• the terminal 11 listening to the signals transmitted by the base station in standby mode, can thus read accessibility information of the secondary networks present on the paging indicator channel.
• the terminal meniôris accessibility information carried by the paging indicator channel When the paging indicators relate to the user group to which the terminal 11 belongs, the terminal meniôris accessibility information carried by the paging indicator channel.
• the paging channel carries a message comprising the identifier of a user and the cause of his request for service.
• the latter decodes the message, while remaining in standby mode.
• the terminal 11 switches from the main network to the secondary network offering the requested service.
• a terminal 11 can directly connect to a secondary network without going through the mode connected with the main network, in order to access a service offered by the secondary network.
• the main network is considered to be of UMTS type, and the paging indicator channel used between the terminal and the main network corresponds to the PICH channel.
• each of the PICH frames comprises 300 bits, of which 288 are used to carry the call indicators and the remaining 12 bits are not used and are not transmitted.
• 288 bits per frame are used to carry call indicators associated with a group of users.
• the remaining 12 bits which were not used according to the techniques relating to the UMTS of the prior art, are used here, so as to prevent the user's terminal from going from sleep mode to connected mode with the network. main to change network.
• this bit is inserted information relating to the type of network on which the terminal can switch.
• these 12 bits comprise accessibility information, relating to the type of available network, according to the desired service. For example, it is possible to use at least 3 bits of the remaining 12 bits of a PICH frame to indicate the type of network, by "encoding" the type of network:
• a GSM network would be encoded by bits '001';
• this set of codes is a simple example, and that other codes, as well as a different number of bits, can be used to indicate the type of network, depending on the desired application.
• the other remaining bits can for example be used to indicate the carrier frequency (via the radio frequency channel number ARFCN, the Absolute Radio Frequency Channel Number), and / or the identity of the cell (CeIl ID ), and / or the type of service, or any other information.
• the remaining 12 bits of at least one of the frames transported by the PICH channel are then transmitted on this PICH channel, with the 288 bits of call indicators.
• the method of switching a main network to a secondary network according to the invention does not require going into connected mode with the main network.
• the terminal 11 listens to the PICH channel during a first step, in standby mode. If the user group to which it belongs is concerned by a message, the terminal stores the last 12 bits of the frames conveyed by the PICH channel, and reads the PCH channel to know to whom the message is addressed.
• PCH Packet Control Channel
• the terminal can decode the message, of the "PagingCause" type and coded on 3 bits according to the UMTS standard, corresponding to the request of the user, and conventionally transported by the PCH channel.
• the user terminal switches to this new network (secondary network) using the accessibility information stored on the last 12 bits of the PICH channel.
• the proposed technique makes it possible to overcome the transition in connected mode to switch to another network, and therefore the establishment of a signaling connection, in a simple and effective manner.
• the ability to stay in sleep mode also helps to avoid an exchange too messages, or adding new messages, while optimizing radio resources.
• the technique implemented thus makes it possible to ensure interoperability and quality of service, and to optimize the allocation of radio resources, depending on the application requested, when several networks of different technology (UMTS, GSM / GPRS / EDGE, WLAN, WWAN, DVB-H ...) are superimposed.
• the invention is of course not limited to a UMTS type main network, and can be applied to any type of radio network. However, if the main network used is of UMTS type, the invention has the advantage of keeping the existing UMTS protocol interface.

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• Engineering & Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)

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Citations (3)

• 2004
  • 2004-07-15 FR FR0407894A patent/FR2873250B1/fr not_active Expired - Fee Related
• 2005
  • 2005-07-06 WO PCT/EP2005/053236 patent/WO2006008241A1/fr not_active Application Discontinuation
  • 2005-07-06 EP EP05761094A patent/EP1774819A1/de not_active Withdrawn

Patent Citations (3)

Non-Patent Citations (1)

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