Method of software download with session mobility support in mobile communication systems

territorially invention

The The present invention relates to the mobile communication Based on the Internet Protocol (IP), and relates particularly to a method for downloading software with support for mobile meetings in mobile communication systems, and to a mobile communication system, where this procedure applies.

background the invention

Mobile communication systems the future about the third generation (3G) also will be characterized by a juxtaposition of a plurality of access technologies such as cellular mobile (in different generations, especially second and third generation), cordless, wireless local area networks (WLAN, Wireless Local Area Network), television systems, wired systems etc. These systems are integrated on a common platform be so that they can mutually complement each other in an ideal way, the diverse service requirements are met. The various access systems are connected to a common, flexible and seamless IP core network ( "Core") to be connected.

In front the increasing use of Internet-like mobile data applications in existing cellular networks is a potential Further development of such networks towards a common definition of transport layer, based on the Internet Protocol IP. The rationale behind this Option can be summarized briefly in the following points: <ul><li>- The Core network and the radio access network have the same transport layer;</li><li>- Base stations with different radio access technologies (RAT, Radio Access Technologies) can using the same transport protocol (IP) with the radio network controller get connected;</li><li>- The cellular mobile phone network and the Internet use the same transport protocol, what the integration of network and application domains facilitated.</li></ul>

Follows Under this approach, it is necessary to use the IP mechanism for managing the mobility of the terminal and so to have a common set of mobility functions are capable of the terminal mobility independently of the radio access technology as well as with respect to the core network in a manage integrated manner. This approach can help the Mobile IP (MIP) and Ipv6 mechanisms are pursued, however, seem will not be suitable for Micro- or pico-mobility. It is anticipated that a hierarchical solution (HMIP) and the application various mechanisms must be integrated to provide a solution for different Mobility scenarios to obtain.

Out establish of clarity, here are some of the definitions of different types of mobility recalled: <ul><li>- Terminal mobility: The ability of the terminal, the to Change Location and yet continue to communicate. Terminal mobility can be: - Discrete Terminal mobility: The ability of the terminal, make discreet relocation as long as no user data be replaced, and this for incoming calls to be within reach. In connection with cellular Mobile means of support Roaming and paging procedures.</li><li>- Continuous Terminal mobility: The ability to change the location, while simultaneously from exchange runs from user data. In connection with the cellular mobile communications, this means supporting the handover procedure. This is called seamless if the QoS (Quality of Service) not due to delays or data loss during affect the handover is.</li><li>- Personal mobility: The ability the end user, on any device at any location (Ie using different access technologies), the / the is covered by his contract to make and receive calls. the means that the network is able, on the basis of the registration information to reach end users and perform localization features, instead based on the terminal information.</li><li>- Session Mobility: The ability the end user, the terminal switch. This can be divided into the following categories: - Discrete Session Mobility: The ability the terminal to change, as long as no user data is exchanged, and this for incoming calls to be within reach. In connection with cellular Mobile means to be able to the meeting a new terminal assign and a new location in the network. - Continuous Session Mobility: The ability, the terminal switch while at the same time user data is exchanged.</li></ul>

to completion of the image may we also define: <ul><li>- Service Mobility: The ability a user, the services for which he is registered, regardless of the location of the user and &lt;?page 3?&gt;execute the terminal used.</li></ul>

the new cellular mobile network will be capable of new value-added services provide that in all probability from the Internet arena submitted and the user via a variety of different radio access technologies (for example, 3G, WLAN, etc.) are provided. The terminal will have the capacity, any support type of access, ie it is a multimodal and, preferably, reconfigurable terminal be. In this scenario, the net all those functions be implemented, the one in support of the reconfiguration terminal are required by efficient use of radio resources. It is obvious, that when changing from one radio access technology to a other (ie upon execution a so-called "vertical Handover "or" VHO ") a multimodal acts or a reconfigurable device such as another terminal, so that the problem that for the change of the terminal relevant mobility features to support, must be ensured by the network.

Among the new services, the downloading of software (software download) be mentioned, wherein the network must be capable of the optimal strategy for its implementation to determine and carry out. The mobile industry is on the verge downloading Media Objects in Styles of the Internet in large scale and independent introduce on the medium type. One of the areas for the use of this technology is the electronic trade, e-commerce. The most probable objects in the initial phase of this business Ringtones, his screensavers, games and Java midlets.

In the scenario described, it may happen that a user a multimodal terminal downloading (download) launches a software and during the Download still running for any reason (beyond the radio coverage area, the need for speeding up the Operation, etc.) must perform a vertical handover, for example by GPRS (General Packet Radio Service, a general packet radio service) UMTS (Universal Mobile Telecommunications Service, universal mobile telecommunications service) or from one cellular mobile radio network a WLAN.

For downloading (Download) software is no real-time requirement in general. In the case of vertical handover thus a serious Problem. The mobility management support during downloading the Software is used by the network operator using the classical SGSN (Service GPRS Support Node) ensured relocation procedure, in which the information is redirected to the new location of the terminal will. However, support this procedure the session mobility during horizontal handovers, in which the terminal the location changes, but in the field of the same radio access network COUNCIL remains. For In case of vertical handover is yet no mechanism implemented with this type of reallocation be overcome can. In this case, the software download should be discontinued and it must, in accordance with identification of the new position of the terminal, the Download the software be started again from scratch.

If the software only has a relatively small extent, affects this Process only slightly on the quality of service QoS and additional Load on the network (ie there are more network resources for retransmission the software used). If the software to be downloaded but a very large Extent, the implementation of mechanisms by which a retransmission is can be avoided, indispensable in order to save radio network resources and to speed up the download procedure. Further, it is possible that download and install a class of software with high priority must be (for example, new operating systems, new radio transmission chains, new protocol stacks, ...). For this class of software also it is important retransmissions to avoid.

In order to it is clear that in a short time the network architecture covers all functionalities must, which are capable of reconfiguration and downloading effective software in a heterogeneous radio access connection to support.

To build and managing an IMS (IP Multimedia Subsystem) session for packet-oriented Services is provided which no real-time constraints have, has the 3GPP (3rd Generation Partnership Project), the proposed Session Initiation Protocol (SIP) as a reference protocol (See for example the 3GPP specification TS 23.228). The SIP protocol is a (signaling) application layer protocol for the establishment, the modification and degradation of meetings with one or more Participant (s) for both Unicast and for Multicast sessions, which in the Internet Engineering Task Force has been standardized (see for example the IETF standard RFC 3261, the subject matter of the document "SIP: Session Initiation Protocol" by J. Rosenberg and H. Schulzrinne is that http://www.ietf.org/rfc.html on the internet site disposal stands).

Of the Use of such a protocol to support the customization of applications for &lt;?page 4?&gt;IP applications while a vertical handover has been already considered, for example, see Paper "End-to-end SIP Based Realtime Application Adaptation During Unplanned Vertical Handover "(Continuous adjustment SIP-based real-time applications in unplanned vertical Handover) of PA Pangalos et al., GLOBECOM '01, IEEE Global Telecommunications Conference, San Antonio (Texas, USA, 25th-29th November 2001), Vol. 6, pp 3488-3493. This paper describes practical tests and includes an evaluation of such Use for vertical handover of mobile terminals on a real-time audio connection involved. As known to real-time traffic is characterized by very strict limitations in terms of time delays out, however, allowed the loss of some data packets during the Handovers. Thus, the proposals contained in said paper are not suitable for a non-profit or forming in real time downloading software, in which a loss of data packets can not be tolerated and it in certain circumstances makes necessary, the entire download package again transferred to. Furthermore, the proposals are the aims paper on the use of so-called "Re-Invite" procedure. Such a procedure but always it off, start a new session after the User has completed the handover, and therefore not suitable to the solution of interest here problem.

tasks of invention

The primary The object of the present invention is to overcome the disadvantages of the current state overcoming art and the Session Mobility while a non-real-time-based process for downloading software ensure in a heterogeneous radio access scheme, in particular in a vertical handover.

Summary the invention

According to a first aspect, the invention is not real-time based on a method Downloading software in an Internet Protocol (IP) based Mobile communication system with heterogeneous access technologies ready in which software download sessions using the Session Initiation Protocol (SIP) to set up and managed. For the resumption of the download process in case of handover between a first and a second Radio access network that use different access technologies while a Software download session is still running, sends the SIP user agent that a handover by leading User terminal connected is without the current session to trigger, upon receipt of a new IP address and a new URL in the second radio access network a Message with a transfer request ( "Refer" message) to a SIP proxy server, the the download session has built and currently manages, with said message information about the address and the URL in the first radio access network, the new URL, the ID of the session and the last software packet contains, has been successfully received, said proxy server is thus informed that the session of the user agent redirect to the new URL, and taking the necessary steps, establish a new session with the user agent at the new URL, under the control of a proxy server, whose job it is, managing the new session and to ensure that the download process beginning resumed at said last received data packet is.

According to a second aspect, the invention provides an Internet Protocol (IP) based mobile communication system prepared with heterogeneous access technologies to a core network at least a serving and gateway mobile switching center and GPRS Support nodes (S-MSC / SGSN and G-MSC / GGSN), and in which a non-real-time-based downloading software in accordance with the above performed procedures described is. In such a system has at least a portion of the user Access to facilities for the not real-time based downloading software and has the compel terminals, to connect to the system via a plurality of said be able to produce access technologies, said terminal the user as well as the system access and the core network are provided with means among other user agent applications and proxy and registrar servers, by which software download sessions through the Session Initiation Protocol (SIP) can be set up and managed. For the resumption of the download process in case of handover between a first and a second Radio access network that use different access technologies while a Software download session still running, is the SIP user agent, the performing a handover User terminal connected is adapted without the current session to dissolve, upon receiving a new IP address and a new URL in the second Radio access network a message with a transfer request ( "Refer" message) to a sending SIP proxy server that has set up the download session and currently manages, said transfer request information to the address and the URL in the first access network, the new URL, the ID of the session and the last software packet contains, the has been successfully received, said proxy server this way is informed that the session of the user agent of the new &lt;?page 5?&gt;URL redirect, and is adapted to the necessary take steps to a new session with the user agent build the new URL, under the control of a proxy server, which Task is to manage the said new session, and the download process starting with said most recently received data packet again is received.

Short description tHE dRAWINGS

The Invention will be better understood from the following description of a preferred embodiment, which is exemplified and without any restrictive character, with reference to the accompanying Drawings, wherein:

<figref idrefs="S44">1</figref> on Reference scenario of the use of the present invention;

<figref idrefs="S44">2</figref> on Block diagram of the reconfiguration and the administration downloading the software units involved into more detail consistently shows;

<figref idrefs="S45">3</figref> on simplified block diagram, the paths of SIP messages for the Software download in a first example of the insert of the invention;

<figref idrefs="S45">4</figref> a Vector of signaling course for the in <figref idrefs="S45">3</figref> illustrated represents download process;

<figref idrefs="S46">5</figref> and <figref idrefs="S46">6</figref> on Block diagram or a graph similar to the <figref idrefs="S45">3</figref> or. <figref idrefs="S45">4</figref> are based on the download of software in accordance with a second example of the use of the invention;

<figref idrefs="S47">7</figref> and <figref idrefs="S48">8</figref> on Block diagram or a graph similar to the <figref idrefs="S45">3</figref> or. <figref idrefs="S45">4</figref> are and resumption downloading of software as in the <figref idrefs="S45">3</figref> and <figref idrefs="S45">4</figref> considered show; and

<figref idrefs="S47">9</figref> and <figref idrefs="S49">10</figref> on Block diagram or a graph similar to the <figref idrefs="S47">7</figref> or. <figref idrefs="S48">8</figref> are and resumption downloading of software as in the <figref idrefs="S46">5</figref> and <figref idrefs="S46">6</figref> considered show.

description the preferred embodiment

<figref idrefs="S44">1</figref> shows schematically illustrates a mobile communication system, in which the present Invention may be used. A terminal UE, which is to get a multimodal terminal or a reconfigurable terminal can act, can access to the above system a plurality of different radio access technologies and thus over different radio access networks Rata, RATB, ... Ratn have. The part of the system that is independent of the access method, according to the terminology 3GPP is called core network and here with CN (= Core Network) in.

The Figure shows an example of the radio access networks Rata, RATB cellular the third and second-generation systems, as well as a wireless local area network (WLAN or hotspot) Ratn. In each block Rati (i = a ... n) the conventional units of the respective mobile communication system with habitual Names or abbreviations indicated, namely Node B and radio network controller RNC (Radio Network Control =) for the network the third generation Rata, radio base station BTS (Base Transceiver = Station) and base station controller BSC (= Base Station Controller) for the Second generation RATB network access point (AP = Access Point) and interworking unit IWU (= Interworking Unit) for the wireless LAN Ratn. These units is here no specific Description required. In the radio access network Rata are two units Node B shown, NB1 and NB2. Analogous to this, the conventional HLR (Home Location Register) and the Serving Gateway and Mobile Switching Centres and GPRS support nodes S-MSC / SGSN or G-MSC / GGSN shown in the core network CN. For reasons of clarity is within the core network CN only considered a single SGSN unit. The connection of this unit with other SGSN units is however represented, as well such as the compounds of the core network CN to fixed-line Internet environment (Through GGSN) and to other core networks (through SGSN).

the terminal UE is assumed to be over the node NB2 connected in the radio access network rata with the system, as shown by the solid line arrow, with the possibility of both horizontal handover (to the node NB1 in the same radio access network Rata) and vertical handover (the radio access network RATB, ... Ratn, represented by the dashed arrow lines) perform.

Around the reconfiguration of the terminal to support and to download software, include the Radio Access Networks Rata ... further Ratn units for managing reconfiguration and downloading operations PRMa, PRMB ... PRMn (= Proxy Reconfiguration Manager), which the Radio network controller RNC, the base station controller BSC or the interworking unit IWU may be associated with or contained in these.

the Core network CN (the home network of the terminal UE in the picture illustrated) with units SRM (Serving Reconfiguration Manager) and HRM (Home Reconfiguration Manager) a hö&lt;?page 6?&gt;heren level equipped, which assigned to the units S-MSC / SGSN and HLR may be present or in this. By "reconfiguration" is in the present Case, the whole of the functions mentioned, which allow a terminal from to switch a radio access method to another, regardless of whether it is a multimodal or a reconfigurable terminal. It should be noted that the terminal where appropriate, for reconfiguration required software including the radio access method to download from the net.

The Units PRMI (i = a ... n), SRM and HRM form a distributed, hierarchical structure with three levels, on the possibilities network domains extend, the HRM unit (Home Reconfiguration Manager) the top and PRMI unit (Proxy Reconfiguration Manager) is the lowest level. A hierarchical distributed structure minimizes network loading and quicker downloading of software.

The Functions of units PRM, SRM, HRM for the reconfiguration and the Software download in a system of the kind as described in <figref idrefs="S44">1</figref> illustrated is to be in the document "Requirements on Network and Security Architecture and Traffic Management Schemes for download traffic based on IP Principles in Cellular and Ad Hoc Networks "(on requirements network and security architecture and traffic management schemes based on IP principles in cellular and ad hoc networks; IST project "SCOUT", document D4.1.1) on the website www.ist-scout.org available stand, and in the document "Reconfigurable SDR Equipment and Supporting Networks Reference Models and Architectures "(Reconfigurable SDR systems and support network reference models and Architectures), White Paper of Working Group 3 of the Wireless World Research Forum (WWRF) (2002). For a better understanding are here but some of the functions of the units PRMI, SRM, HRM briefly described.

For such Description Reference is also made to the <figref idrefs="S44">2</figref>, There for simplicity only two radio access networks are considered, For example, a UMTS network RAT1 (also called "cellular") and a WLAN RAT2 ( "hotspot") The reconfiguring devices are. here in the radio network controller RNC, the interworking unit IWU, the SGSN unit (Service GPRS Support Node) and the home location register HLR included and are suitable memory units (repositories) SP1, SP2, SS, SH1 allocated, SH2, which more fully hereinafter is treated. To ensure consistency with<figref idrefs="S44">1</figref> contain both networks RAT1, RAT2 a respective proxy reconfiguration manager PRM1, PRM2, even if a WLAN like RAT2 the proxy reconfiguration manager the cellular mobile radio network auskäme. Since PRM1, PRM2 same SRM unit (Serving Reconfiguration Manager) connected in the core network CN are, the radio access networks and RAT1 RAT2 deemed to same Terminal Reconfiguration Serving Area duly characterized by the as dashed line block shown TBSA. The description for<figref idrefs="S44">2</figref> puts mainly with the aspects related to downloading Software apart.

The Proxy Reconfiguration Manager devices PRMI (i = 1, 2) form the Contact points for each terminal, that is connected to the radio access networks Rati. These units are mainly its features for Mode monitoring, Mode negotiation, participates mode switching and downloading the software. For the Negotiation and information processes will control traffic of and sent to the PRMI-units, whereas in the case of downloading transported by software the appropriate software data packets over the PRMI units will. These units may be be divided into two parts, the functions of the user level, (Blocks sprei in <figref idrefs="S44">2</figref>Wherein SPRE stands Software Download and Profile Repository) and the functions of the control level (Block SDRC in <figref idrefs="S44">2</figref>Wherein SDRC is the abbreviation for software Download and Reconfiguration Controller) represent. The blocks sprei capture all profiles and other information that is responsible for carrying out Reconfiguration and for downloading software are required.

Further it is the responsibility of these blocks, the software modules from the respective memory unit or the appropriate repository retrieve SPi and to transmit it to the terminal. Generally, the repository SPi is a cache memory for frequently requested software (Reconfiguration software for the terminals the corresponding radio access network RAT or other software) on higher Levels is stored, but it can also be a part of the software contain to the terminal can be forwarded. Because frequently requested software in PRMI (Proxy Reconfiguration Manager) is included, the for the implementation the download is needed time considerably reduced and also the network of a large part of the traffic is relieved, so that the network resources can be used more efficiently. The block SDRC houses, as its name suggests, the control functions for the Reconfiguration and download. Specifically, it controls the processing the request for downloading of software modules, which in the associated storage unit SPi are included, and forwards the request to the higher levels, if not, the software &lt;?page 7?&gt;is included in the SPI unit.

The Unit SRM (Serving Reconfiguration Manager) is compatible with all PRMI units connected in their TBSA (Terminal Radar Serving Area) and is equipped with a Memory means SS linked, where among other things the reconfiguration software for all radio access method are contained in said TRSA. The storage means includes SS a current software database and can under certain circumstances a cache memory for software comprise the higher of a Plane comes. As the PRMI units can also Serving Reconfiguration Manager SRM in two blocks C-SRM and U-SRM are subdivided that for the functions of the control or the user level responsible are.

The functionality the control level, C-SRM, has two main tasks: <ul><li>- Manage the corresponding exchange of control messages between the terminal (via the Proxy Reconfiguration Manager PRM and special about the Software download and reconfiguration controller SDRC) and the units AAA processes (authentication, authorization and accounting) Managing in the public network when the user perform a handover or a software component want to download, for the authorization is required;</li><li>- Location update (Or macro mobility function): The Serving Reconfiguration Manager SRM stores the location of each controlled terminal in his TRSA: For example, if a mass upgrade pending, SRM must know which proxy reconfiguration manager PRM the software module must be forwarded.</li></ul>

The functionality the user level, U-SRM, the SRM is in turn the function of providing the software downloads responsible by she requests Software receives, neither in the unit PRMI the radio access network Rati, the currently is used, nor is included in the neighboring PRM units. The U-SRM functionality provides the proxy reconfiguration manager PRM requested Software ready when it is stored in the memory means SS; otherwise directs the U-SRM functionality the request in turn further to the Home Reconfiguration Manager HRM, where the software is transferred to the PRM once they procured has been.

The HRM unit must provide all software available, the lower the Levels is not available, including new software upgrades over the it is informed by the providers, and can with a plurality SRM units (Serving Reconfiguration Manager) be connected. In the case of Upgrades notified of HRM the SRM on the availability new software and forwards it to the SRM as necessary. Goes at the HRM tables a question for downloading software is, he also the authorization of the terminal jurisdiction, provided that the software is licensed, and for the settlement of software downloads with the user. In this case, HRM uses a billing repository, which is updated when the related software download is. Block SH1 shows the whole of the software databases, the for the HRM over the servers of the respective manufacturers are available, shown in Whole by block MS, and the block SH2 represents the billing Repository (Or the AAA server). The latter server is also connected to the control plane part C-SRM of SRM connected.

According to the invention are the software download sessions using the SIP protocol such managed that mobile sessions are supported. The SIP is a text-based client-server protocol to the Simple Mail Transfer Protocol (SMTP) and the HyperText Transfer Protocol (HTTP) was designed. As with any other text-based client-server protocol gives the client requests and provides the server returns responses. to the understanding facilitate, are hereafter some definitions of SIP components and Functions that occur in the invention for use, again listed: <ul><li>- The "User-Agent Client "(hereinafter you just called "SIP client") is the calling user agent, that is, a client application that initiates a SIP request;</li><li>- The "Proxy" (or "proxy") is an intermediate program which functions both as a server and as a client, with the purpose to get requests on behalf of other clients; inquire be handled internally or passed on to other servers, possibly after a previous translation;</li><li>- The "registrar" is a server, accepts the registration requests and usually together with one Proxy server is installed;</li><li>- "Invite" is the procedure, which is used for establishing a connection;</li><li>- "Register" is the procedure, by means of which transmit a user location information to a server may allow the server a next address of a previous address can assign, under which the user is reachable;</li><li>- "Bye" is the procedure for the Degradation of the meeting.</li></ul>

Around the Session Mobility ensure the present invention also uses the "Refer" method. In this The procedure is a recently standardized SIP extension, the many applications possible makes, Darun&lt;?page 8?&gt;ter for example, the call forwarding. The "Refer" method shows in that the receiver the redirection message, the request by the URI (Universal Resource Identifier) ​​is in contained in the request on the basis of Contact information to a third party to contact. The "Refer" method is in the IETF standard RFC 2315 describes the subject matter of the document "The SIP Refer Method "(The SIP Refer method) by R. Sparks is that on the internet site http://www.ietf.org/rfc.html to disposal stands.

Of the Establishing a session for downloading software and the resumption in the event of vertical handover will now be described with reference to the block diagrams and graphics of the <figref idrefs="S45">3</figref> to <figref idrefs="S49">10</figref> described. from the terminal UE it is assumed that it is connected to the radio access network RAT1 is, when the download is started, and that, during the Download process is a vertical handover to the radio access network RAT2 performs.

The Block diagrams in <figref idrefs="S45">3</figref>. <figref idrefs="S46">5</figref>. <figref idrefs="S47">7</figref> and <figref idrefs="S47">9</figref> show the SIP components concerned by the invention, as well as the paths of SIP messages, the latter by the bold arrow lines are shown. In detail, dashed lines for the "Register" messages; solid lines for the "Invite" - and "OK" messages (in a single bi-directional arrow summarized); dot-dash Lines for the "Refer" messages used. A dotted line arrow denotes the download and a broken Double line denotes the checks in the repositories. Units, which are also in the<figref idrefs="S44">1</figref> and <figref idrefs="S44">2</figref> contain are represented by the same reference symbols. In favor of the simplicity of the pictures were the standard units omitted in the mobile communication system the block diagrams and are only for the download of software management of reconfiguration and required units shown since these are the units which the SIP components accommodation. On the other hand, the arrangement of these administrative units below with respect to the units of the mobile communication system Referring to <figref idrefs="S44">1</figref> and <figref idrefs="S44">2</figref> illustrated. Also the memory unit SH2 and the manufacturer server MS were the greater clarity omitted.

The Block diagrams clearly show that according to the invention a hierarchical Structure of SIP proxies is proposed to provide a flexible and scalable solution to develop. Specifically:<ul><li>- Home to the terminal UE a SIP client (CL), the start the registration phase and the session must, if the download request is initiated by the terminal itself;</li><li>- accommodation units PRM1, PRM2 and SRM respective SIP proxy server PX1, PX2, PX3 (which the first point of contact for form the SIP client and assume the construction and management of the meeting) and registrar server RG1, RG2 and RG3, which registry the the terminal make the net.</li></ul>

As already mentioned above, is a single unit SGSN (Service GPRS Support Node) considered, which is connected to the radio access networks RAT1 and RAT2, and exemplified the case of downloading software in the memory unit SP1 (<figref idrefs="S45">3</figref>. <figref idrefs="S45">4</figref> and <figref idrefs="S47">7</figref>. <figref idrefs="S48">8</figref>) or SS (<figref idrefs="S46">5</figref>. <figref idrefs="S46">6</figref> and <figref idrefs="S47">9</figref>. <figref idrefs="S49">10</figref>) present. Accordingly, only two levels are shown in the SIP structure. The proposed solution but is open to an expanded architecture in every respect, for example, the case where the radio access networks with different COUNCIL SGSN units get connected. Indeed the method is scalable and successfully to more complex Architectures applicable.

In the graphics used following identifiers for the SIP components: <ul><li>- Source Address the terminal (SIP client): user1@rat1.core.net</li><li>- SIP client address after relocation: user1@rat2.core.net</li><li>- PX1: prm1@rat1.core.net</li><li>- PX2: prm2@rat2.core.net</li><li>- PX3: srm@core.net.</li></ul>

It Reference will now be made to the <figref idrefs="S45">3</figref>. <figref idrefs="S45">4</figref>; the process of establishing a session for downloading software the proxy reconfiguration manager PRM1 is as follows: <ul><li>1. The SIP client (the terminal UE) performs the Registering with the SIP proxy server in PX1 PRM1 by;</li><li>2. The REGISTER message is stored in the registrar server RG1 and then forwarded at the proxy server the higher level PX3 in SRM (Serving Reconfiguration Manager). Subsequently the identifier of the terminal UE stored in the SRM level in SIP register RG3.</li><li>3. The SIP client sends an INVITE message to the PRM1, to start the SIP session. The message (where it the present for Invention information of interest concerns) could about as follows appearance: INVITE prm1@rat1.core.net Via [prm1@rat1.core.net] from user1@rat1.core.net to prm1@rat1.core.net Call ID xyz123</li><li>4. The PRM1 checks whether the software in its Re&lt;?page 9?&gt;pository SP1 is included. The answer is positive.</li><li>5. From the proxy server PX1 an OK message is sent back to the terminal UE, so that the session is established and the software download to the terminal started UE properly is.</li></ul>

the Software download follows the rules, which defines the SIP. note is that the proxy PX1 does not store the downloaded software, even if a certain degree of buffering is of course provided, around the PX1 incoming and outgoing traffic from there adapt. The arrow "SW Download "in the Signaling diagram extends from the proxy to the client, as it refers to the control signaling and not to the actual data packets.

In the above message and the messages that are related with the <figref idrefs="S46">6</figref>. <figref idrefs="S48">8</figref> and <figref idrefs="S49">10</figref> be mentioned, is not expressly Referring to the structure of the message (query line, headboard, Text part), since the structure is the same as by the standards defines the SIP protocol and of the present invention not affected is. We call here only remembered that the text part a number of parameters (known as SDP parameters, where SDP for session Description Protocol is) which contain the information, among other things, for example, about the session features, time, and details of those used in the session Media. A list of these parameters is to be inserted at this point not necessary, since they are defined in IETF standard RFC 2327, the already mentioned on the above web site of the IETF can be found. One of the parameters that describe the session characteristics (Example, the parameter s = name of the session or the parameter i = information about the session), indicates that at the meeting it by downloading the desired Software module goes. Furthermore, since the invention aims a software download process from the last received data packet to resume, when a vertical handover occurs, necessary the consecutive number pktn of downloaded data packets track: For this purpose can the optional session attribute lines (parameter a) are used. Of the two SDP parameters above is only the "packet number" parameter explicitly shown (In the messages concerning the recovery phase).

Becomes downloaded the software from the Serving Reconfiguration Manager SRM (<figref idrefs="S46">5</figref>. <figref idrefs="S46">6</figref>), The user starts a Session with PRM1, as before, too, and repeats the steps 1 to 4 above. The "Register" messages and the "Invite" message to the Proxy servers are in PX1 <figref idrefs="S46">5</figref> for reasons of clarity of the drawing no longer represented. In that case, verification provides in If the requested software included step 4 in the repository SP1 is a negative result. Then, the following steps are performed:<ul><li>5. If the PRM1 detects that the software to be downloaded, is not included in the repository SP1, it sends to the terminal UE a "Refer" message to the existing session to the SIP proxy of the higher Level (ie SRM) redirect. The PRM1 (Referred by, Diverted of) notifies the terminal UE (user1, user1) with that the existing session (Call ID, Call-ID) to the SRM (Refer, rerouting must be redirected to). The "Refer" message may like look like this: REFER user1@rat1.core.net Via [prm1@rat1.core.net] from prm1@rat1.core.net to user1@rat1.core.net Call ID xyz123 Refer to srm@core.net Referred by prm1@rat1.core.net</li><li>6. Upon receipt of the "Refer" message sends the terminal UE a new INVITE message to the proxy server PX3 in Serving Reconfiguration Manager SRM. The new INVITE message looks like this: INVITE srm@core.net Via [prm1@rat1.core.net] [srm@core.net] from user1@rat1.core.net to srm@core.net Call ID xyz123</li><li>7. Assuming that the presence of the software in the memory unit SS is known in advance, then an OK message is sent back to the terminal UE. The session is established and software download starts. Is the presence of the software in the storage unit SS not known in advance, a check is after the INVITE message 6 similar to that carried out in Step 4 (The review is in <figref idrefs="S46">5</figref> shown).</li></ul>

In both cases the session is dismantled after completion of the download process (through the Message BYE, not shown in the graphics), provided that the terminal UE still located in the radio coverage area of ​​RAT 1.

It Note that the "Register" message, and if the download is on the PRM level, to all Registrars of higher levels is passed, so that the higher levels of the location of the terminal know. This is advantageous when it comes to handling the recovery one download session goes, as will become apparent below.

&lt;?page 10?&gt;

It the case will be described that the terminal UE during the download process from one location UE (1) in the radio coverage area of ​​RAT 1 to a Location UE (2) (dotted lines) in the radio coverage area changes from RAT2. If the software from the repository SP1 of Proxy Reconfiguration Manager is PRM1 downloaded (<figref idrefs="S47">7</figref> and <figref idrefs="S48">8</figref>) it is assumed that such software also in repository SS of the serving stored reconfiguration manager SRM. In the<figref idrefs="S45">3</figref> and <figref idrefs="S46">5</figref> illustrated Headlines in the <figref idrefs="S47">7</figref> and <figref idrefs="S47">9</figref> not longer included. The introduced in the radio access network RAT 1 download process continues shown, but with thinner Lines.

In <figref idrefs="S48">8</figref> will in steps 1, 2 of the current download process and the vertical Handover shown. In radio coverage area of ​​RAT2 the terminal receives a UE new IP address and a new URL, in this case user1@rat2.core.net. The mobility the terminal is according to MIP (IPv6) mechanisms handled. These are conventional mechanisms and must therefore will not be discussed at this point again closer.

After Receipt of the new IP address is the terminal UE informed that it is in a different subnet, and tried the software download session to resume. Together with other SIP parameters has the terminal UE the Identification of pre-existing session (Call ID, Call ID), the current Number of the last correctly received Data packet (SDP parameter "pktn") and his old URL stored. The terminal UE sends a "Refer" message to the Proxy server PX1 (step 3 in <figref idrefs="S48">8</figref>), to the redirect ongoing session to his new URL. The message includes among other things, the old URL (field "Referred by" Redirected through) and can follow look: REFER user1@rat2.core.net Via [prm2@rat2.core.net] [srm@core.net] From user1@rat2.core.net To prm1@rat1.core.net Call ID xyz123 Refer to user1@rat2.core.net Referred by user1@rat1.core.net SDP Pktn 1453

Of the Proxy server PX1 is for configured not to respond to the message "Refer"; the message is simply ignored, but it receives the new URL of the terminal UE, the Call ID and the reference to the last correctly received data packet (Step 4 in <figref idrefs="S48">8</figref>).

then sends the proxy PX1 a further "Refer" message ( "Refer" message no. 5, triggered by "Refer" message no. 3) to the serving reconfiguration manager SRM to the previously under the redirect old URL structured session. The new "Refer" message has the Purpose, the SRM also informing that an identified by the Call ID parameter Session with the terminal UE needs to be made under this new URL and that the SRM same software again to retrieve from its repository and the Download starting has to start at the given data packet. This second "Refer" message looks as follows from: REFER user1@rat2.core.net via [srm@core.net] From prm1@rat1.core.net To srm@core.net Call ID xyz123 Refer to user1@rat2.core.net Referred by user1@rat1.core.net SDP Pktn 1453

Of the Serving Reconfiguration Manager SRM sends an INVITE message to the terminal UE at this new URL (user1@rat2.core.net): INVITE user1@rat2.core.net Via [Prm2@rat2.core.net] From srm@core.net To user1@rat2.core.net Call ID xyz123 SDP Pktn: 1453

the terminal UE accepts the new session by sending back an OK message (step 7 in <figref idrefs="S48">8</figref>). The download of the software from the storage unit SS resumed and begins again at the packet, wherein the download process is interrupted (ie, the packet 1453); after the new session is established correctly, the old still pending session reduced.

The <figref idrefs="S47">7</figref> and <figref idrefs="S48">8</figref> show, that, even if the session has been started at the PRM level (by PRM1), the resumption by the next higher level, ie by the Serving Reconfiguration Manager SRM, is managed, not at the peer level by PRM2 in radio access network RAT2. This decision was reasons taken the simplicity of signaling, taking into account was that a very high degree of Signaling would be required to manage the download process to be transmitted to the PRM2. On the other side it is in general rather rare to a vertical Handover, so that the load of the SRM would not significantly increased. Further is due to this decision, an improvement the delay characteristics, even if this is not of decisive is important because it is not real-time-based traffic.

&lt;?page 11?&gt;

In the case, that the software download is resumed from SRM (<figref idrefs="S47">9</figref> and <figref idrefs="S49">10</figref>) is similar to the procedure: Of course takes place during the resumption no intervention PRM1. Specially sends the terminal UE now a "Refer" message to the SRM, at the current session redirect to its new URL: REFER user1@rat2.core.net Via [prm2@rat2.core.net] From srm@core.net To prm1@rat2.core.net Call ID xyz123 Refer to user1@rat2.core.net Referred by user1@rat1.core.net SDP Pktn: 1453 and sends the SRM to the terminal UE an INVITE message as before. The further course corresponds to the above-described case.

As already mentioned the invention is based on a hierarchically expandable structure the SIP server. Therefore, if the devices have the possibility or the need, downloading software modules from the repository SH1, the home is Reconfiguration manager HRM also a proxy and a registrar server accommodation; in this case, at least when the location of the Software is not known beforehand, forwarded the "Register" message to the HRM. If the execution of the software downloads the intervention of HRM is required, of course, even with the resumption of the download process such intervention of HRM be necessary.

in the generally leaves said that a software download session, identified by the proxies of the lowest Plane was built, resumed by a proxy of the next higher level (PX3) , while a session that has been established through a proxy a higher level, can be resumed from the same proxy, where they built has been.

In the case that the target radio access network RAT2 with another SGSN unit (Service GPRS Support Node) is connected as the SGSN unit, which is connected to the radio access network RAT1, the hierarchical Structure is preferably characterized exhausted, that the restoration of is managed by the Home Reconfiguration Manager HRM (ie the top of the hierarchy). In this case, the "Refer" message is sent to the Serving Reconfiguration Manager SRM (3 or 5, depending on how the case is) a "Refer" message to the HRM trigger when the software is downloaded from the SRM or the PRM1, whereas the "Refer" message from the client directly to the HRM is sent when the software is downloaded from the HRM. The HRM then sends the INVITE message to the client under whose new URL.

The "old" SGSN unit could Intervention of the "new" SGSN unit also direct request, which then send the INVITE message to the client would, although this is a less preferred alternative.

It is obvious that the above description only exemplary in nature and has no limiting character and that changes and modifications possible are, without departing from the scope of the invention as in the accompanying claims is defined.

Therefore the present invention, even if they reference herein on a "conventional" mobile communication system has been described, even in a future mobile communications systems Generation can be used profitably. Since the invention to the Using the SIP protocol based, it can just as well as an application of an IMS platform or in general as a means the integration of reconfigurable functionalities in a IMS architecture are used.