WO2007015084A1

WO2007015084A1 - Transmitting information from a mobile terminal directly to other mobile terminals

Info

Publication number: WO2007015084A1
Application number: PCT/GB2006/002870
Authority: WO
Inventors: Byron Bakaimis
Original assignee: Samsung Electronics (Uk) Limited
Priority date: 2005-08-01
Filing date: 2006-08-01
Publication date: 2007-02-08
Also published as: GB0515825D0; GB2428935B; GB2428935A

Abstract

A mobile terminal for use in a cellular communications network, the terminal being adapted to transmit information originating from said terminal directly to one or more mobile terminals.

Description

TRANSMITTING INFORMATION FROM A MOBILE TERMINAL DIRECTLY TO OTHER MOBILE TERMINALS

The present invention relates to short-range mobile telecommunications service. More particularly, but not exclusively, the invention relates to a short- range mobile telecommunications service to transmit personalised information to a plurality of mobile terminals.

A cellular communications system includes mobile user equipment (UEs), a radio access network (RAN) and one or more core networks (CNs), as illustrated in Figure 1 for the UMTS case. A detailed overview over the architecture of a cellular telecommunications system of the third generation may be found in the 3GPP specification "UTRAN Overall Description" 3GPP TS25.401 and related specifications. Communication between the UEs and the UTRAN is provided via the Uu interface (Uu), whereas the communication between the UTRAN and the core networks is done via the Iu interface (Iu). Figure 2 illustrates the architecture of a radio access network. The RAN comprises base stations 2, such as the so-called Node B's for the UTRAN, and radio network controllers 4 (RNC), also referred to as base station controllers (BSC). The base stations 2 handle the actual communication across the radio interface, covering a specific geographical area also referred to as a cell. Each cell may be split into sectors, wherein each sector effectively is a cell of its own. In UMTS a Node B has normally three or six sectors.

The RNC 4 controls the base stations 2 connected to it, and also includes other functionality for tasks such as the allocation of radio resources, i.e. the local mobility. An RNC 4 is connected to one or more core networks 8 via the Iu interface 12, to a number of base stations 2 via the Iub interface 10 and possibly to one or more other RNCs 4 via the Iur interface 14.

Referring to Figure 3, a UE 100 may comprise a microphone 16, a loudspeaker 18, a transmit and recieve antenna structure 20, a numeric keypad or other data entry device 21, a cursor control keypad or other control input device 23, and a screen display device 26, together with a battery, a data input/output port, and a control circuit comprising a microprocessor, ROM and RAM (conventional and hence not discussed further). In a UMTS network, the Radio Resource Control (RRC) protocol is used across the radio interface, i.e. between the UE and UTRAN

If one user wishes to send information to a plurality of users, there are different possibilities foreseen in the communications networks. The information considered here is information originating from the user or from the UE, also referred to as personal information in the following.

One possibility is to send the information via a Group Short Message Service (SMS). Referring now to Figure 4, the process of sending a Group SMS will be briefly described.

The user of UE 201 likes to send information to a plurality of UEs 203, also referred to as the target group of UEs in the following. In order to do so, the user of UE 201 needs to compose the SMS, i.e. enter the information into the terminal in the well-known manner, or make use of information stored in the UE. The SMS is then sent on the uplink, first through the Uu interface to the Node B 207, and then via the RNC 209 to the core network 211. In order to send the SMS to the target UEs 203, databases of the recipients, such as

HSS (Home Subscriber Server), home location register (HLR) and/or visiting location register (VLR) need to be questioned to identify the UEs and query other information or databases with reference to billing/security/location etc.

On the down link the SMSs are then transmitted in the opposite direction, first to the RNCs 209 and to the Node Bs 207serving the target UEs 203, and then over the Uu interface to the individual UEs 203 of the target group of UEs.

A disadvantage of distribution information via a Group SMS is that a high volume of downlink (DL) unicast signalling is required to send the SMS to the target group of UEs. This causes interference also over the air interface. This is due to the fact that all SMS messages of the group SMS are transmitted individually via the Iu/Iub/Uu interfaces from the core network to the plurality of UEs. Particularly in case that the target UEs are located in the vicinity of UE

201 the use of radio resources appears not particular efficient. If the UEs are close to each other, but are served by different Node Bs/RNCs, the signalling load is even higher.

The above described method allows for a multicast service (i.e. group of people having known phone numbers), but does not support a broadcast service (i.e. a group of people with unknown phone numbers) Another possibility would be to use the existing MBMS service. However, MBMS as described in the Release 6 does not support the provision of personal information, i.e. information originating from the UE 201.

Such an extended MBMS services, however, might be provided by using the uplink (UL) to transmit the information from the originating UE to the network. Subsequently, the core network can then send the information through MBMS transmission to the target group of UEs.

With regard to the signalling, the implementation is similar to the group SMS described above. The user enters the information he or she would like to send into the UE. The information is then signalled via the UL to the core network (through Node B and the RNC). The information is then "mapped" to the MBMS Radio Bearers or Radio Access Bearers (RBs/RABs) and sent through a Multicast and/or a Broadcast mode all over the cell (or cells) serving the target group of UEs. For the same reasons as described above with respect to the group SMS, such a solution might not be a very efficient use of the radio capacities in case that the target UEs are in the vicinity to the UE 201. Also, the method might cause increased interference and raise security issues, as a user would be enabled to upload personal information into the network with the danger of that being non-legitimate content e.g. viruses etc.

Another potential disadvantages in case that the target UEs 203 are located in the vicinity of the originating UE 201 is that, in broadcast mode, the information is distributed to all UEs within one or more cells of the network rather than in the vicinity of the originating UE. The larger the cell is, the more the "waste" of transmitting to UEs that are not requested.

It is therefore an aim of the present invention to alleviate the described and other disadvantages of the services and methods described above. According to one aspect of the present invention, there is provided a mobile terminal for use in a cellular communications network, the terminal being adapted to transmit information originating from said terminal directly to one or more mobile terminals.

Preferably the one or more mobile terminals are located in the vicinity of said mobile terminal.

In this way a localised distribution of information originating from a user is provided through an efficient handling of network resources. The service exploits the spatial vicinity of target group to the originating user.

The service works similar to a peer-to-multi-peer communication, but in a cellular concept.

According to another aspect of the present invention, there is provided a network element of cellular communications network, the element being adapted to allocated resources to a mobile terminal, such that the terminal can transmit information originating from said terminal directly to one or more terminals.

According to yet another aspect of the present invention, there is provided method of communicating via a cellular communications network by a multicast and/or broadcast service, whereby a mobile terminal transmits information originating from said terminal directly to one or more mobile terminals.

Preferably, the service may support a broadcast and/or multicast service.

Preferably, the UE negotiates with a network element through uplink and downlink signalling to acquire radio recourses from the network.

Other aspects of the present invention are set out in the appended claims.

Embodiments of the present invention will now be described, by example only, with reference to the accompanying figures, whereby

Figs. 1 and 2 are schematic outlines of a mobile communications network, in which the present invention can be incorporated;

Fig. 3 is a schematic diagram of a mobile terminal in which the present invention can be incorporated;

Fig. 4 is a schematic diagram illustrating the provision of a group SMS service according to the prior art; Fig. 5 is a schematic diagram illustrating the provision of a multicast and/or broadcast service according to one embodiment of the present invention;

Fig.6 is a flow chart diagram illustrating the multicast and/or broadcast service according to another embodiment of the present invention. In the following, the process of providing a UE with the resources to transmit a personal multicast and/or broadcast message will be described, referring to Figure 6. The process starts in step 301 if the user wishes to transmit information to a plurality of user terminals. In step 303 the XJE signals a request for the allocation of radio resources to a network element. The network element is usually the RNC or the core network. In the request, the user specifies the UE's capabilities, the desired transmittal radius, the desired Quality of Service (QoS) and other possible attributes such as the time period required to transmit the information, and the type of application (SMS, MMS, Video, MP3). The request is then transmitted via the radio link to the Node B and further either to the RNC or to the core network. Whichever the network element is, it will still use information from any other element e.g. if the network element is the RNC then it will also use information from the CN network elements e.g. SGSN or the other way around.

In step 305, the network element (NE) receives the request and identifies the specified requirements. In step 307, the network element determines its current capabilities to provide the desired resources, hi addition, the network element determines what effect the provision of the desired radio resources might have on other, ongoing communications (step 309) for instance the induced interference. Subsequently, the network element allocates the resources to the UE (step 311). The network element may allocate the resources in the same way as requested by the UE, i.e. the UE may be allocated radio resources over the requested time period, at the requested QoS etc. However, in case that the desired radio resources are not available or would disturb or interfere with the ongoing communications and/or regular demand, the network element may alternatively allocate resources according to its current capabilities.

In step 313, the network element signals the allocated configuration of the allocated radio resources to the UE. Li step 314 the UE reads the signalled radio resource configuration.

In step 315, the user of the originating UE may not be satisfied with the allocated radio resources. Thus, the user may try to re-negotiate the allocation of the radio resources with the network element. The user may signal a second request to the network element, specifying the minimum requirements he or she needs to transmit the information. The network element can then check again the resources and may, for example, offer an improved allocation of radio resources to different conditions.

On returning to step 315 once more, the user can then decide whether he or she agrees to the offer. The user may for example agree to a higher fee for providing the improved service. Alternatively, the user may prefer to wait for a certain time until the desired allocation of radio resources becomes available. On settling the configuration, the UE subsequently configures itself to acquire the allocated radio resource in step 316.

In step 317 the UE can then transmit the personal information to the target group of UEs using the allocated radio resources. This can be done either as a broadcast or as a multicast service. In the following Figure 5 is referred to. The originating UE 201 sends his request for allocation of radio resources to the Node B 207. The request is then transferred either to the RNC 209 or to the core network 211. As above described with reference to Figure 6, a network element of the core network or the RNC negotiates the provision of radio resources via the communications links 230 both in uplink and downlink direction.

After a suitable configuration has been found, the radio resource configuration to be allocated to the UE is signalled to the UE 201 on the downlink. The originating UE 201 can then configure itself to acquire some basic base station capabilities such that the UE 201 can then directly signal the personal information via the radio link 232 to the target group 203 of UEs located in the vicinity of the originating UE 201. Again, the UE 201 may transmit the information either as a multicast or a broadcast message/mode. This solution is, from a signalling point of view, much more efficient than the transmission of the group SMS described above with respect to Figure 4, as the information or data can be directly signalled from the originating UE 201 to the target group of UEs 203 located in the vicinity of the UE 201. In order to transmit the information directly to a number of target UEs

203, the UE 201 acquires a scrambling/spreading code with some specific parameters and acts temporarily as a base station. This can be done similar to a UE acting as a mobile relay to provide the broadcast and/or multicast information. However, the information transmitted by the UE 201 is provided by the user or UE 201 directly rather than by the network. In this way the information transmitted can be individual and personalised.

The scrambling code to be allocated to the originating UE 201 needs to be different to the scrambling code used in the sectors of both the serving and surrounding cells.

In order to ensure that the UE 201 is allocated a scrambling code different to the one used for the sectors of the serving and surrounding cells, the codes for the different cells are allocated in advance to any request for a personal multicast or broadcast service in the cell planning process. Thus, a scrambling code selected from a pool of "available" scrambling codes is allocated for each cell and each sector at any time. In order to minimise the inter-cell interference, the codes selected for the pool of scrambling codes in a particular cell are those codes which are used in cells far away from the cell considered.

If now a UE requests the provision of radio resources to transmit personal information, a scrambling code from this "pool" can be assigned to one UE for providing the service. The codes should be allocated after realtime optimum network planning. It is noted that interference resulting from the transmission of information between the UE 201 and the target group of UEs 203 to the other cells will be minimal due to the very limited transmission energy of the UE 201. The larger the serving cell and the smaller the coverage of the originating UE 201, the lower the induced interference.

The interference to the transmission of the originating UE 201 caused by neighbouring, on the other hand, might be relatively high. This is due to the fact that the transmission power of the UE 201 is relatively low, such that the received power from the UE 201 at one of the target UEs might be comparable to the attenuated power received from the surrounding cells. However, as the UEs 203 of the target group are situated in close vicinity to the originating UE 201 the reception of the target UEs will not be significantly degraded due to inter-cell interference. The smaller the distance between the target UEs and the originating UE is and the larger the serving cell is, the less the interference to the target UEs is induced.

The UE needs to acquire Base Station-like capabilities. However, as it will support only broadcast/multicast services it does not need to have all the BS functionalities. For instance, there is no need for Closed Loop Power Control or Downlink Dedicated Physical channels to the UEs. Thus, the basic requirement is for the UE to transmit its information through a Logical Broadcast channel mapped to a Broadcast Transport channel mapped to a Broadcast Physical channel. In the case of UMTS the Logical Broadcast Control CHannel (i.e.

BCCH) is mapped to the Transport Broadcast CHannel i.e. (BCH) which is mapped onto the physical channel of CCPCH i.e. Common Control Physical CHannel. A possible additional requirement is the transmission from the UE of a pilot channel like the CPICH i.e. Common Pilot CHannel in the case of UMTS. In general this can be used for channel estimation, handover processes etc. Thus, in the present embodiments, the CPICH could be used to assist the target UEs to handover temporarily to the UE to receive the personalised MBMS. No additional requirements in terms of channels are envisaged.

Thus, in the general sense, the UE should be allocated the relevant scrambling and spreading codes and then, once the user has defined the data to be transmitted, the UE will perform the usual mapping of those data from the logical to the transport to the physical channels, which channels will be spread and scrambled like in the usual/normal case of a BS. The mapping and the setting up of those channels e.g. the type of transport channels, will be based on information that will be communicated to the UE from the network after the resource-negotiation process.

It is envisaged that the receiving UEs are able to receive the multicast or broadcast information provided by originating UE 201 in parallel to other communications such as a voice call. This can for example be implemented by providing the UE with a dual receiver or by other means. In this way the receiving UEs may directly receive the information from the UE 201. Still, reception can be done even with one receiver. Alternatively, the UE 201 may, before transmitting the multicast or broadcast information to the group of UEs 203, signal to the target group of UEs that it will be sending multicast or broadcast information shortly to inform the group of users. The UEs 203 of the target group can then switch to reception of the multicast or broadcast service or otherwise prepare for the reception should this be necessary.

In the broadcast mode, the UE then provides a broadcast channel similar to the common Node B broadcast channels. However, the broadcast channel provided by the UE is locally restricted. The channel may for example be provided with a certain restricted transmission power, such that a predetermined transmission radius is achieved. Some kind of synchronisation among the broadcast channels of the serving cell and that of the originating UE might be required. For example, the UE may request the transmission of information within a radius of 5m if the user is located in a small meeting room, or may request the transmission within a radius of 20m if he or she is in a large conference room, hi this way the user ensures that the 'personal' information can be transmitted to other persons located in the same room. The transmission range given above is the transmission range for a free path, i.e. if no walls or buildings or other obstacles are in the way between the transmitting UE 201 and the group of UEs 203. We assume that a fair request from users will be done.

The same applies for the multicast. The only difference is that some kind of key needs to be distributed among the users of the multicast group in order to restrict other users receiving that content. That could be a password that can be transmitted verbally in advance to the users. That also could be in the form of a question and answer to the users of the multicast group. In general, multicast and broadcast modes from the network side are the same (e.g. content is transmitted all over the same area). The content is also received by all users. However, the main difference is whether the end user can "see" the content after e.g. entering the password. The network element 213 determines the allocation of radio resources with help of a radio resource management (RRM) element. With help of a RRM algorithm the RRM element estimates the impact of providing the required service, i.e. possible resulting interference for providing the UE 201 with the radio resources etc. The algorithm takes into account the requested QoS, the requested transmission radius, the time period of the transmission and the type of application, such as SMS, the transmission of pictures or video date etc.

According to the estimated interference and possible degradation of the ongoing services the network element 213 allocates or refuses to allocate resources.

It is understood that the provision of such a service has several implementation issues which can be addressed similarly to other services provided. These issues include for example the structure of channels provided by the UE, charging and billing issues and security issues. It might be possible to receive in parallel User Equipment-Multimedia

Broadcast/Multicast Services (UE/AP -MBMS) and Access Point -MBMS (AP/UE -MBMS). Whilst the above described embodiments have been described in the context of UMTS, it is appreciated that the present invention can also be applied to other similar systems.

It is to be understood that the above described embodiments are set out by way of example only, and that many variations or modifications are possible within the scope of the appended claims.

Claims

CLAIMS:

1. A mobile terminal for use in a cellular communications network, the terminal being adapted to transmit information originating from said terminal directly to one or more mobile terminals.

2. A mobile terminal according to claims 1, wherein the terminal is adapted to transmit said information as a multicast and/or broadcast service.

3. A mobile terminal according to claim 1 or 2, wherein the mobile station is provided with base station capabilities.

4. A mobile terminal according to claim 1, 2 or 3, wherein the one or more mobile terminals are located in the vicinity of said mobile terminal.

5. A mobile terminal according to any preceding claim, wherein the mobile terminal is adapted to negotiate the provision of signalling capabilities with a network element.

6. A mobile terminal according to any preceding claim, wherein the mobile terminal is adapted to request the provision of signalling capabilities in the uplink.

7. A mobile terminal according to any preceding claim, wherein said mobile terminal is adapted to receive information regarding the provision of signalling capabilities from a network element.

8. A mobile terminal according to claim 7, wherein said information includes a scrambling code and one or more spreading codes.

9. A mobile terminal according to any preceding claim, adapted to configures itself to provide signalling capabilities.

10. A network element of a cellular communications network, the element being adapted to allocate resources to a mobile terminal, such that the terminal can transmit information originating from said terminal directly to one or more mobile terminals.

11. A network element according to claim 10, adapted to receive a request for the provision of radio resources from a mobile terminal.

12. A network element according to claim 10 or 11, adapted to determine its current capabilities and the capabilities of the network to provide signalling resources to a mobile terminal.

13. A network element according to claim 10, 11 or 12, adapted to estimate the impact of providing signalling resources to a mobile terminal to other communications links.

14. A network element according to any of claims 10 to 13, adapted to allocate or provide signalling resources to a mobile terminal.

15. A network element according to any of claims 10 to 14, adapted to negotiate the provision of signalling capabilities with the mobile terminal.

16. A network element according to any of claims 10 to 15, adapted to provide the mobile terminal with information for the use of the network resources.

17. A method of communicating via a cellular communications network by a multicast and/or broadcast service, whereby a mobile terminal transmits information originating from said terminal directly to one or more mobile terminals.

18. A method according to claim 17, wherein a network element allocates network resources to the mobile terminal.

19. A method according to claim 18, wherein the network resources include providing the mobile station with some base station capabilities.

20. A method according to claim 17, 18 or 19, wherein the one or more mobile terminals are located in the vicinity of said mobile terminal.

21. A method according to any of claim 17 to 20, wherein the mobile terminal negotiates the provision of signalling capabilities with a network element.

22. A method according to claim 21, wherein the mobile terminal requests the provision of signalling capabilities in the uplink.

23. A method according to claim 22, wherein in response to the mobile terminal's request, a network element provides the mobile terminal with information for the use of the network resources.

24. A method according to any of claims 17 to 23, wherein said information includes a scrambling code and one or more spreading codes.