WO2015144251A1

WO2015144251A1 - Multimedia broadcast-multicast service

Info

Publication number: WO2015144251A1
Application number: PCT/EP2014/056366
Authority: WO
Inventors: Bernhard Wegmann; Henri Markus Koskinen; Ahmad AWADA
Original assignee: Nokia Solutions And Networks Oy
Priority date: 2014-03-28
Filing date: 2014-03-28
Publication date: 2015-10-01

Abstract

When a user apparatus is receiving an MBMS service via a unicast bearer, the user apparatus is configured to send to a radio access network information identifying the unicast bearer and the MBMS service received via the unicast bearer.

Description

DESCRIPTION

TITLE

MULTIMEDIA BROADCAST-MULTICAST SERVICE

FIELD

The present invention relates to multimedia broadcast-multicast service in a mobile communication system.

BACKGROUND ART

The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with dis-closures not known to the relevant art prior to the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.

In recent years, the phenomenal growth of mobile Internet services and proliferation of smart phones and tablets has increased a demand for mobile broadband services. A multimedia broadcast-multicast service (MBMS) is designed to provide application-independent transport for broadcast and multicast services by using a point-to-multipoint interface. Examples of services and applications that can be pro- vided over MBMS include mobile TV and radio broadcasting, streaming video, streaming audio, file delivery and emergency alerts. MBMS user service provisioning and delivery are provided by a functional entity called Broadcast Multicast Service Centre (BM-SC), and an MBMS user service may be delivered in a specific area on broadcast/multicast bearer services, or on unicast bearer services. However, the use of MBMS services is transparent to a radio access network when conveyed over unicast bearers, and sparse unicast resources may be wasted.

SUMMARY

A general aspect of the invention provides a radio access network with information on an MBMS service and a unicast bearer reserved for the MBMS service. Various aspects of the invention comprise methods, apparatuses, a system and a computer program product as defined in the independent claims. Further embodiments of the invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

In the following, embodiments will be described in greater detail with reference to accompanying drawings, in which

Figure 1 shows simplified architecture of an exemplary system; Figures 2 and 3 are charts illustrating exemplary functionalities;; and

Figures 4 and 5 are schematic block diagrams of exemplary apparatuses.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

The following embodiments are exemplary. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations, this does not nec- essarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

The present invention is applicable to any system, radio access network, a network element, or a corresponding component and a user apparatus (user equip- ment) configured to support multimedia broadcast-multicast services. The system may be a wireless system or a system utilizing both fixed connections and wireless connections. The specifications of different systems and networks, especially in wireless communication, develop rapidly. Such development may require extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment.

A general architecture of an exemplary system 100 providing multimedia broadcast-multicast services is illustrated in Figure 1. Figure 1 is a simplified system architecture only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The connections shown in Fig- ure 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the systems also comprise other functions and structures that are not illustrated.

Below different examples are illustrated assuming that an MBMS service is delivered using broadcast transmission provided by one or more Multimedia Broad- cast Single Frequency Network (MBSFN) areas or the service is delivered using unicast transmission if MBSFN transmission for that service is suspended, without limiting the examples to such a solution. An MBSFN area consists of a set of cells transmitting synchronously the same signal. The MBFSN transmission may be suspended because the number of user apparatuses interested to receive an MBMS ser- vice by broadcast is small.

In the embodiment illustrated in Figure 1 , the system 100 comprises a radio access network 101 providing access to the system for user apparatuses 1 10 (UE, user equipment, only one shown in Figure 1 ) by means of access point nodes 120 (only one shown in Figure 1 ), the radio access network being connected to a Broadcast Multicast Service Centre (BM-SC) 130 for delivery of MBMS services.

The user apparatus 1 10 refers to a portable computing device (equipment), and it may also be referred to as a user terminal or mobile terminal. Such computing devices (apparatuses) include wireless mobile communication devices operat- ing with or without a subscriber identification module (SIM) in hardware or in software, including, but not limited to, the following types of devices: mobile phone, smart- phone, personal digital assistant (PDA), handset, laptop and/or touch screen computer, e-reading device, tablet, game console, notebook, and multimedia device. The user apparatus 1 10 is configured to support MBMS with unicast/broadcast change. For that purpose the user equipment 1 10 comprises an enhanced MBMS unit 1 1 1 whose functionality will be described in more detail below. It should be appreciated that the user apparatus 1 10 is depicted to include 2 antennas only for the sake of clarity. The number of reception and/or transmission antennas may naturally vary according to a current implementation.

The access point node 120, or any corresponding network entity (network apparatus, network node), may be for a wireless system or for a system utilizing both fixed connections and wireless connections, and the access point node may be configured to support one or more wireless access. Examples of such systems/networks include LTE/SAE (Long Term Evolution/System Architecture Evolution) radio system, Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), advanced LTE (LTE-A), and/or beyond LTE-A, and any com- bination thereof.

In the example of Figure 1 , an evolved node B 120 (eNB) depicts the access point node and hence the radio access is based on LTE/SAE (Long Term Evolution/System Architecture Evolution) radio system, the radio access network 101 being E-UTRAN (evolved UMTS terrestrial radio access network). The evolved node B 120 provides the E-UTRA user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the user apparatus 1 10. The evolved node B 120 is configured to receive from user apparatuses information on an MBMS service(s) and unicast bearer(s) reserved for the MBMS service(s). For that purpose the evolved node B 120 comprises an MBMS bearer unit 121 whose functionality will be described in more detail below. It should be appreciates that herein the term "MBMS service" covers any service of similar type, regardless how it is actually named. For example, in LTE the service is called as an enhanced MBMS (eMBMS).

As illustrated in Figure 1 , evolved node B 120 is connected to BM-SC 130. BM-SC provides functions for MBMS user service provisioning and delivery. BM-SC may serve as an entry point for content provider MBMS transmissions, used to authorize and initiate MBMS Bearer Services within a network and may be used to schedule and deliver MBMS transmissions. However, the present invention does not affect to BM-SC, and therefore it is not described in more detail here.

Figure 2 is a flow chart illustrating an exemplary functionality of a user ap- paratus. More precisely, it describes exemplary functionality of the enhanced MBMS unit.

Referring to Figure 2, the user apparatus has indicated interest to receive MBMS service A in an area in which the service is delivered via unicast bearers. Therefore a data radio bearer DRB1 is received in step 201 for the MBMS service A, the data radio bearer DRB1 being a unicast bearer between the user apparatus and a radio access network when the user is receiving the service. Then the user apparatus detects in step 202 a trigger event. Basically the trigger event is an event relating to MBMS services. Depending on an implementation, the user apparatus may be configured to interpret one or more of the following as a trigger event: the user apparatus is to be handed over from one cell to another cell; the user apparatus enters an MBFSN area, for example the user apparatus receives a system information block (SIB) 13 indicating an MBMS control channel, MCCH; the user apparatus enters an MBFSN area for the service A; the user apparatus receives an advertisement advertising MBMS services, like a system information block (SIB) 15; the user apparatus receives an inquiry or a specific request to report MBMS services received on unicast bearers, for example SIB15 having a service area identity (SAI) indicating that according to an application-layer user service description the service A is supposed to be available; and/or a time period after a previous sending of the information has lapsed. It should be appreciated that the above list of trigger events is not an exhaustive list, and any suitable event may be used as a trigger event. Because of the trigger event, the user apparatus sends in step 203 to a radio access network an indication that the MBMS service A is received on DRB1. The indication may be sent by adding the indication/information to an MBMS Interest Indication signaling message, for example. If more than one service is received on unicast data bearer, they all may be sent in the same message. Naturally, if the trigger event requests information on a specific MBMS service that the user apparatus is receiving on a unicast bearer, then information only on the service is sent. Further, in the illustrated example it is assumed that MBFSN area for the service A has been entered and therefore the user apparatus changes in step 204 from DRB1 to a mul- ticast radio bearer (MRB) for the service A. In other words, the user apparatus stops using the unicast delivery of the service A and starts to use the broadcast delivery of the service A.

It should be appreciated that step 204 may be omitted. Further, if the trigger event may be that the user apparatus changes from DRB1 to MRB, i.e. steps 202 and 204 are integrated and step 203 is performed after them.

Figure 3 is a flow chart illustrating an exemplary functionality of an access node, in the illustrated example the enhanced node B (eNB). More precisely, Figure 3 describes exemplary functionality of the MBMS bearer unit .

When the eNB receives in step 301 an indication from a user apparatus (UA1 ) that the user apparatus is using a unicast data radio bearer DRB1 for the MBMS service A, the eNB is able to identify the unicast data radio bearer which is used for the MBMS service A. This is especially useful information in situations in which the user apparatus UA1 has more than one unicast data radio bearers for more than one service (unicast service or MBMS service) running in parallel. Without the indication of DRB1 , i.e. without identifying the data radio bearer, the eNB could not know which bearer is used for which purposes.

Then in the illustrated example, the eNB checks in step 302, whether or not the eNB is broadcasting on multicast radio bearer MRB the service A. Thanks to indicating the service in the message, this checking may be performed.

If the service A is sent on MRB, thanks to the indication of DRB1 , the eNB knows which bearer should be released and releases in step 303 the unicast data bearer. Thanks to releasing the unicast data bearer, radio resources are not wasted for unicast delivery of a service available also on the broadcast at the same location. This releasing of DRB1 may be called coordinated switching, controlled switching, forced switching or coordinated service-based channel assignment. Then, in the illus- trated example, the eNB is further configured to send in step 304 information on the user apparatus using the service A to a multicast coordination entity (MCE) which is a logical entity in the network and is responsible for the allocation of time and frequency resources for multi-cell MBMS transmission. Thanks to the information, MCE can keep track on the amount of user apparatuses interested for the service A in a location. However, it should be appreciated that step 304 may be omitted.

In addition to the checking performed in step 302, the eNB may be configured to obtain, before releasing DRB1 in step 303, some certainty that the user apparatus has changed to use MBR. The certainty may be obtained by using MBFSN measurement reports received from the user apparatus UA1 as one criterion, for example, and/or monitoring that the user apparatus UA1 has been in the MBFSN service area a certain time period.

If the service A is not sent on MRB (step 302), the eNB sends in step 304 information on the user apparatus using the service A to MCE. In another example, the eNB omits step 304 and starts to wait for next indication.

The steps/points, messages and related functions described above in Figures 2 and 3 are in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Other functions can also be executed between the steps/points or within the steps/points, and other messages sent. Some of the steps/points/messages or part of the steps/points/messages can also be left out or replaced by a corresponding step/point/message or part of the step/point/message. For example, the eNB may receive from MCE a request to inquiry from user apparatuses in the service area of the eNB whether they are interested to receive MBMS service X or are receiving it as a unicast service, and the eNB then forwards the received responses to MCE without performing steps 302 and 303.

It should be appreciated that although in the above it is assumed that one unicast bearer is used for receiving one MBMS service that need not to be the case; one MBMS service may require two or more unicast bearers, or two or more MBMS services shares the same unicast bearer. It is apparent to a person skilled in the art how to implement the above examples in such cases.

The techniques described herein may be implemented by various means so that an apparatus implementing one or more functions of a corresponding apparatus described with an embodiment/example/implementation comprises not only prior art means, but also means for implementing the one or more functions of a corre- sponding apparatus described with an embodiment and it may comprise separate means for each separate function, or means may be configured to perform two or more functions. For example, the enhanced MBMS unit and/or the MBMS bearer unit and/or algorithms may be software and/or software-hardware and/or hardware and/or firmware components (recorded indelibly on a medium such as read-only-memory or embodied in hard-wired computer circuitry) or combinations thereof. Software codes may be stored in any suitable, processor/computer-readable data storage medium(s) or memory unit(s) or article(s) of manufacture and executed by one or more processors/computers, hardware (one or more apparatuses), firmware (one or more appa- ratuses), software (one or more modules), or combinations thereof. For a firmware or software, implementation can be through modules (e.g., procedures, functions, and so on) that perform the functions described herein. Software codes may be stored in any suitable, processor/computer-readable data storage medium(s) or memory unit(s) or article(s) of manufacture and executed by one or more processors/computers.

Figure 4 is a simplified block diagram illustrating some units for an apparatus 400 configured to be a user apparatus, i.e. an apparatus comprising at least the enhanced MBMS unit. In the illustrated example the apparatus comprises one or more interfaces (IF) 401 for receiving and transmitting information over the radio access network, one or more user interfaces (U-IF) 401 ' for interaction with a user, a proces- sor 402 configured to implement at least the enhanced MBMS unit functionality described herein with a corresponding algorithm/algorithms 403 and a memory 404 usable for storing a program code required at least for the codec. The memory 404 is also usable for storing other possible information.

Figure 5 is a simplified block diagram illustrating some units for an appa- ratus 500 configured to be a network apparatus (access point) comprising the MBMS bearer unit, or corresponding functionality. In the illustrated example, the apparatus comprises an interface (IF) 501 for receiving and transmitting information over the radio access network, a processor 502 configured to implement at least the MBMS bearer unit functionality described herein, with corresponding algorithms 503, and memory 504 usable for storing a program code required for the MBMS bearer unit and the algorithms. The memory 504 is also usable for storing other possible information.

In other words, an apparatus configured to provide the user apparatus, and/or an apparatus configured to provide the network apparatus, or an apparatus configured to provide one or more corresponding functionalities, is a computing device that may be any apparatus or device or equipment configured to perform one or more of corresponding apparatus functionalities described with an embodiment/example/implementation, and it may be configured to perform functionalities from different embodiments/examples/implementations. The unit(s) described with an apparatus may be separate units, even located in another physical apparatus, the distributed physical apparatuses forming one logical apparatus providing the functionality, or integrated to another unit in the same apparatus.

The apparatus configured to provide the user apparatus, and/or an apparatus configured to provide the network apparatus, or an apparatus configured to provide one or more corresponding functionalities may generally include a processor, controller, control unit, micro-controller, or the like connected to a memory and to various interfaces of the apparatus. Generally the processor is a central processing unit, but the processor may be an additional operation processor. Each or some or one of the units and/or algorithms described herein may be configured as a computer or a processor, or a microprocessor, such as a single-chip computer element, or as a chipset, including at least a memory for providing storage area used for arithmetic operation and an operation processor for executing the arithmetic operation. Each or some or one of the units and/or algorithms described above may comprise one or more computer processors, application-specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field-programmable gate arrays (FPGA), and/or other hardware components that have been programmed in such a way to carry out one or more functions of one or more embodiments/implementations/examples. In other words, each or some or one of the units and/or the algorithms described above may be an element that comprises one or more arithmetic logic units, a number of special registers and control circuits.

Further, the apparatus configured to provide the user apparatus, and/or an apparatus configured to provide the network apparatus, or an apparatus configured to provide one or more corresponding functionalities may generally include volatile and/or non-volatile memory, for example EEPROM, ROM, PROM, RAM, DRAM, SRAM, double floating-gate field effect transistor, firmware, programmable logic, etc. and typically store content, data, or the like. The memory or memories may be of any type (different from each other), have any possible storage structure and, if required, being managed by any database management system. The memory may also store computer program code such as software applications (for example, for one or more of the units/algorithms) or operating systems, information, data, content, or the like for the processor to perform steps associated with operation of the apparatus in accordance with examples/embodiments. The memory, or part of it, may be, for example, random access memory, a hard drive, or other fixed data memory or storage device implemented within the processor/apparatus or external to the processor/apparatus in which case it can be communicatively coupled to the processor/network node via various means as is known in the art. An example of an external memory includes a removable memory detachably connected to the apparatus.

The apparatus configured to provide the user apparatus, and/or an apparatus configured to provide the network apparatus, or an apparatus configured to pro- vide one or more corresponding functionalities may generally comprise different interface units, such as one or more receiving units and one or more sending units. The receiving unit and the transmitting unit each provides an interface in an apparatus, the interface including a transmitter and/or a receiver or any other means for receiving and/or transmitting information, and performing necessary functions so that the infor- mation, etc. can be received and/or sent. The receiving and sending units may comprise a set of antennas, the number of which is not limited to any particular number.

Further, the apparatus may comprise other units.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A method comprising:

receiving an multimedia broadcast-multicast service via a unicast bearer; and

sending to a radio access network information identifying the unicast bearer and the multimedia broadcast-multicast service received via the unicast bearer.

2. A method as claimed in claim 1 , further comprising:

detecting a trigger event; and

sending the information in response to detecting the trigger event.

3. A method as claimed in claim 2, wherein the trigger event is the entering into a new service area and/or receiving an advertisement advertising multimedia broadcast-multicast services and/or receiving an inquiry requesting information on one or more multimedia broadcast-multicast services received via one or more unicast bearers.

4. A method as claimed in claim 1 , 2 or 3, further comprising

detecting that the service is provided via a multicast or broadcast bearer; and

starting to use the multicast or the broadcast bearer for receiving the mul- timedia broadcast-multicast service.

5. A method comprising:

receiving, in a radio access network, from a user apparatus, information identifying a unicast bearer and an multimedia broadcast-multicast service received by the user apparatus via the unicast bearer.

6. A method as claimed in claim 5, further comprising:

releasing, in response to the multimedia broadcast-multicast service being delivered via a multicast or broadcast bearer in a service area of the user apparatus, the unicast bearer.

7. A method as claimed in claim 5 or 6, further comprising:

sending information identifying the multimedia broadcast-multicast service to a multicast coordination entity.

8. A method as claimed in claim 5, 6 or 7, further comprising: requesting from the user apparatus information on multimedia broadcast- multicast services delivered using one or more unicast bearers.

9. A user apparatus comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are con- figured to, with the at least one processor:

send to a radio access network information identifying at least one multimedia broadcast-multicast service received via one or more unicast bearer and the one or more unicast bearers.

10. An radio access network apparatus comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor:

receive, from a user apparatus, information identifying a unicast bearer and an multimedia broadcast-multicast service received by the user apparatus via the unicast bearer.

1 1. An apparatus comprising means for implementing a method as claimed in any of claims 1 to 4.

12. An apparatus comprising means for implementing a method as claimed in any of claims 5 to 8.

13. An apparatus as claimed in claim 10, wherein the apparatus is configured to be an access point or an evolved node B.

14. A computer program product comprising program instructions configuring an apparatus to perform any of the steps of a method as claimed in any one of claims 1 to 8 when the computer program is run.

15. A system comprising:

at least one radio access network comprising at least one apparatus as claimed in claim 12 or 13; and

at least one apparatus as claimed in claim 1 1.