User Equipment Operations and Maintenance measurement concept for Multimedia Broadcast and Multicast Services

Field of the invention The present invention concerns a method in connection with a multimedia service transmission intended for multiple receivers over a terrestrial radio network according to the preamble of claim 1. Further, it concerns a receiver for reception of a multimedia service transmission intended for multiple receivers over a terrestrial radio network according to the preamble of claim 28.

Background of the invention

Terrestrial broadcast services for small mobile devices with small antennas, such as Mobile TV in mobile phones, is an area that has gained a lot of attention. For instance, Multimedia Broadcast and Multicast Services (MBMS) has been defined and developed for GSM and WCDMA mobile systems. Also, for CDMA2000 there is a similar concept. In addition, standalone broadcast systems has been developed, e.g. DVB-H (Digital Video Broadcasting Handheld). All of the these technologies, and related technologies, for terrestrial broadcast services for small ( = could be carried by a person) mobile devices, are subsequently referred to as MBMS.

It is possible to implement an MBMS system that is optimized for broadcast services, that only uses a Downlink (DL), i.e. non-duplex communication where information flows over the wireless interface only in the direction from Base-Station (BS) to User Equipment (UE). A particular benefit of a downlink only system is that no radio spectrum resources are needed for an uplink (UL). Radio carrier and spectrum resources are needed only for the DL. Another benefit is that the radio characteristics of an UL can be ignored, and thus, efficiency-optimized DL-only Base-Stations with high output power and good coverage can be developed for such systems. Such MBMS systems, that only uses a wireless DL, is subsequently referred to as MBMS dedicated carrier (DC) systems or shortly Dedicated Carrier (DC) systems.

Terrestrial wireless systems that have MBMS functionality or techniques, and also can handle UL transmissions on radio spectrum resources that are either the same as

for the DL, or paired with spectrum resources of the DL, are referred to as MBMS mixed carrier (MC) systems, or shortly mixed carrier (MC) systems. The UL in a MBMS MC system could be used for UL signalling and/or for non-MBMS services requiring an UL, e.g. unicast services, see below.

Terrestrial wireless systems that has the capability of point-to-point communication between the BS and the UE, UL or DL or both, is subsequently referred to as Unicast capable system, or shortly Unicast (UC) systems. Typical UC user services include voice-calls, video-calls, internet web-browsing, sending a message etc.

A common deployment scenario for MBMS DC systems is that such a system is overlaid on a UC network, meaning that the DC and UC systems overlap in geographical coverage. The overlaid DC and UC systems may use the same or different network equipment and network resources or a combination. For example, such scenarios has been foreseen in discussions in 3GPP, where an MBMS DC system typically would be overlaid on a UC GSM (Global System for Mobile communications), WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution) network, and a typical UE would be capable of MBMS services distributed by MC or DC, and UC services.

To be able to detect performance problems, do troubleshooting and to be able to correctly tune configurable parameters in telecom systems, techniques of cyclic collection of data, typically statistics data and counters, are used. These kinds of techniques are used for all major terrestrial wide-area wireless systems of today, e.g. GSM or WCDMA systems. Typically such data would be collected from every network node at regular interval, e.g. every 15 minutes. Such data would then be post- processed in an operation and maintenance (O&M) system, which typically would calculate Key Performance Indicators and maybe generate immediate operator alarms if performance drops below certain levels. Performance reports for human reading would also be generated at regular intervals, to trigger manual corrective actions. Also, it could be possible to automatically generate input data to other systems to support tuning of the system. Typically, such data, in its post-processed form, would be used for troubleshooting, network tuning and network resource need determination in various scenarios, e.g. at initial network installation, at further equipment extension

installations, to verify performance and correct operation after software upgrades and to detect problems that can otherwise not be detected. Such data collected in these ways, and used in these kinds of techniques are subsequently referred to as counters or statistics data.

In wireless systems of today that employ said data collection and performance evaluation techniques, the counters or statistics data collected are typically associated with successful, unsuccessful or uncompleted telecom procedures in the call control plane or user plane, e.g. number of detected Random Access Attempts, Number of successful Random Accesses, number of User Equipment (UE) sessions setup, number of dropped UE sessions in different UE states etc.

In the known art and in order to allow troubleshooting and other activities in an MBMS system, there is a possibility for a UE to do measuring and reporting statistics data. For 3GPP MBMS Rel-6, the UE can be requested to do a statistics report after session completion, see 3GPP TS 26.346, Multimedia Multicast/Broadcast Service (MBMS), protocols and codecs. The request is embedded in data that the UE receives at service discovery / service announcement. The existing mechanism includes the reporting of quality metrics such as Corruption Duration, Rebuffering duration, Initial buffering, Successive loss of RTP packets, Frame Rate deviation and Jitter Duration.

The existing mechanism includes functionality for spreading reporting over time and to request only a fraction of the UEs to report, to reduce load peaks.

However, there are problems with the current design of MBMS systems. For instance, in case of a poor radio coverage of the radio network transmitting an MBMS service, then for a MC (mixed carrier) MBMS system there might be a problem for the receiver (UE) to report back. In the first place, the receiver might not even be able to properly receive MBMS transmissions from the transmitter due to fading or other coverage problems. Even though the UE might receive a request for a report from a base station, the conditions may be such that the comparatively weak transmitter of the UE might not be enough to get through to the base station. In that case the base station will notice that there was no reply, but would be in the dark concerning the cause.

As to the case of a downlink only system, there are of course no means at all for reporting anything to a base station, since there is no up-link. Nevertheless, such a system may for instance also experience service outages and troubleshooting of such systems must generally be conducted by car.

Summary of the invention

It is an object of the present invention to propose a solution for or a reduction of the problems of prior art. A main object is consequently to propose a method by which operation and maintenance of a Multimedia Broadcast and Multicast Services (MBMS) system is simplified.

According to the invention this is accomplished with a method having the features of claim 1.

This method makes it possible, in an MBMS system, to detect, measure and analyze problems, related to the transmission, by sending information relevant to the transmission over a different network, to be able to correct/tune the radio access network. This could be accomplished for a Multi Carrier system, also when the uplink and/or downlink of that system is subject to disruptions/interference. Also, in the case of a MBMS Dedicated Carrier (downlink only) system for which the network itself cannot maintain such statistics data, a means for reporting is realised by claim 1.

According to another aspect of the invention the above object of the present invention is accomplished with a receiver having the features of claim 28.

This receiver makes it possible, in an MBMS system, to detect, measure and analyze problems, related to the transmission, by having the receiver adapted to sending information relevant to the transmission over a different network, to be able to correct/tune the radio access network. This could be accomplished for a Multi Carrier system, also when the uplink and/or downlink of that system is subject to disruptions/interference. Also, in the case of an MBMS Dedicated Carrier (downlink only) system for which the network itself cannot maintain such statistics data, a means for reporting is realised by claim 1.

Other beneficial features of the invention are disclosed in the dependent claims.

Brief description of the drawings Embodiments exemplifying the invention will now be described, by means of the appended drawings, on which

Fig. 1 illustrates a User Equipment (UE) doing statistics measurements and reporting to a network,

Fig. 2 illustrates different ways for a User Equipment (UE) to report information, Fig. 3 illustrates UE measurement control.

Detailed description of the invention

Typically, in contemporary wireless systems counters or statistics data is maintained per network entity, e.g. per Cell, per location area, and not really maintained per session. Normally, the UE itself does not directly collect or deliver or participate in any collection such counters. The counters that are related to the wireless radio interface are collected in the network end. The UE does indeed do measurements that are reported to the network (Base Station etc), but those are generally not intended for O&M post processing and performance evaluation. UE measurements are instead usually used for real-time machine-implemented algorithms, e.g. to trigger a handover, to trigger an up-switch of bitrate etc. AU counters or statistics data are commonly collected from the network (Base Station etc). One main reason, in the past, to avoid that counters or statistics data are measured in and collected from UE:s is to avoid the extra load on the wireless interface for reporting.

As indicated in the earlier section, network operators typically initiate network tuning based on results of statistics data collection and post-processing. This is how the network is optimized, e.g. protocol parameters are optimized to give best experienced user performance, radio and antenna parameters are optimized for good coverage etc. Network tuning for optimization is a continuous process in the operation of a network.

Statistics data also has an important role in problem detection, e.g. if certain functions or certain resources fail completely, the network performance would drop to low levels. Such failures might be difficult to detect with other means than statistics data.

MBMS DC systems are particularly problematic in this respect. As there is no two way interactions over the wireless interface for such a system, there is also no statistics data counters to collect in the network that relates to the user experience of the transmission. There are no successful, unsuccessful, completed or uncompleted procedures in the wireless user plane or control plane to count.

Nevertheless MBMS DC systems have geographical coverage issues and a need for tuning of radio and antenna parameters. There are possibilities for function and resource failures that are hard to detect. Thus, there is a need for functionality that fulfils the same purposes as outlined for statistics data collection.

In order to overcome the drawbacks of the prior art, a new method in connection with a multimedia service transmission intended for multiple receivers (or UE:s) over a terrestrial radio network, wherein the multimedia service transmission intended for multiple receivers being sent from a radio transmitter to at least one receiver is proposed. The method includes the steps:

- forming in the at least one receiver, information relevant for the multimedia service transmission intended for multiple receivers,

- feeding back the information to a management entity using a different communications means separate from said terrestrial radio network, so as to allow an adjustment of the multimedia service transmission intended for multiple receivers in respect of said information on the multimedia service transmission intended for multiple receivers. The multimedia service transmission intended for multiple receivers could for instance be of broadcast or multicast type.

In this way it is possible for the receiver or UE to use a communication mechanism that is separate from MBMS radio bearers or separate from the MBMS system, to report the result of statistics measurements and counters. In particular, a UC system overlaid with an MBMS system can be used for reporting of results. This is especially interesting if the MBMS system is a DC system. In particular, for a MC system, the

UE could use communication mechanisms related to general control of UE, or communication mechanisms related to UC and/or UC services for the reporting of results. This also implies the benefit of making it possible to avoid the extra

complexity of having particular communication mechanisms that are MBMS related, for reporting, for the MBMS MC deployments.

The information relevant for the multimedia service transmission could for instance include at least one quality measure for the multimedia service transmission. In order to form such quality measures, the UE could do performance related measurements and maintain counters that are related to the user experience and the radio transmission reception of MBMS transmission. Subsequently, the UE would report the results to a management entity, for instance in the network. Radio transmission quality has not been considered in the prior art in relation to MBMS transmissions.

A benefit of the above is that it makes it possible to report results pointing to possible problems, related to the user experience and reception of transmission, to be able to correct/tune the network, also in the case of MBMS DC. This makes it possible to detect, measure and analyze problems, related to the user experience and reception of transmission, to be able to correct/tune the radio access network, without having to invent particular procedures to maintain statistics data and counters in the network, in the case of MBMS MC.

UE STATISTICS

Currently, in prior art, there are some measurements defined for how to determine MBMS performance. However, those measurements are session related, and to do RAN troubleshooting, e.g. to compare the received Quality of UEs in different locations for UEs potentially receiving different sessions, these measurement results first need to be added or averaged with respect to received session length. As the received session length for certain services, e.g. 3GPP MBMS broadcast services, is not available to the network (e.g. due to no explicit join or leave operations), the current prior art measurements cannot be used for this purpose. Furthermore, current measurements cannot be correlated with radio interface measurements or geographical information, which is needed to be able to focus improvement actions efficiently.

CLASS BASED COUNTERS

The method according to the invention could in one embodiment include that the at least one quality measure includes time spent by the receiver while receiving data

with a reception quality within certain predefined boundaries. Such as in a quality of service class.

With respect to the MBMS error-rate-measurements, error-rate thresholds could be defined (as a result of research) to set the limits to distinguish a number of Quality-of- service (QoS) Classes, e.g. three such classes could be named "good", "acceptable" and "poor", reflecting the perceived quality of MBMS reception. It is further proposed to measure the amount of time spent in each of the QoS-classes that is defined, alternatively the amount of data or frames received in a certain QoS class could be defined.

By this kind of measurement the results from several UEs can easily be added together by adding the time/amount of data/no of frames each UE spent/received in a specific QoS Class to form statistics measurement results for the whole network or a part of the network, with respect to the QoS Classes. Alternatively, relative time/amount of data/no of frames could be used to calculate average time/amount of data/no of frames for every QoS class including many UEs to form a network metric.

In general, by managing class based counters, counting a number of events over a certain time period, and reporting those counters instead of reporting every measured event separately, the required load on the UE and the wireless interface is greatly reduced. This is applicable to all class based counters mentioned in this document.

If the measurement result is requested immediately, the average QoS class of a few sampled frames could be reported.

In that way, the number of UEs reporting a certain QoS class could be summed or averaged to form QoS class metrics for the network. This could be particularly useful when the UE does the measurement on a test transmission and the User do not want to see the transmission. Also, this makes it possible to have a short measurement to minimise the impact on UE battery life.

CLASS BASED COUNTERS FOR COVERAGE - QUALITY - DESIGNS

It is assumed that some MBMS applications and the Radio Bearer technology that carries the MBMS media stream(s) are designed in such a way that there is significant difference in coverage for different perceived QoS levels, e.g. a media application could be divided into different streams which would be transmission-coded differently 5 for different coverage. Only the most robustly coded stream would have "full" coverage, and it would provide a "basic" level of perceived QoS to the end user. As a UE moves into better radio conditions, also less robustly coded streams could be received, adding to the data that is correctly decoded, adding to the user-perceived QoS. 0

For this kind of system, it is proposed to measure the amount of time/amount of data/no of frames received in each of these QoS classes as defined by QoS-coverage design of the system, e.g. class C = receiving one stream correctly (with an error rate below a certain threshold), class B = receiving two streams correctly (with an error 5 rate below a certain threshold), class A = receiving three streams correctly (with an error rate below a certain threshold).

By that kind of measurement, the results from several UEs can easily be added together by adding the time/amount of data/no of frames each UE spent/received in a O specific QoS Class to form statistics measurement results for the whole network or a part of the network, with respect to the QoS Classes. Alternatively, relative time/amount of data/no of frames could be used to calculate average time/amount of data/no of frames for every QoS class including many UEs to form a network metric.

5 If the measurement result is requested immediately, the average QoS class of a few sampled frames could be reported.

In that way, the number of UEs reporting a certain QoS class could be summed or averaged to form QoS class metrics for the network. This could be particularly useful O when the UE does the measurement on a test transmission and the User do not want to see the transmission. Also, this makes it possible to have a short measurement to minimise the impact on UE battery life.

GENERAL QUALITY PER RECEIVER (UE)

The method according to the invention could in one embodiment include that the at least one quality measure includes at least one radio network quality parameter.

User experience and user satisfaction is hard to measure directly. Instead it is proposed to measure MBMS radio reception error rate. A mapping between "average" user experience/satisfaction and MBMS radio reception error rate could be produced by research on this topic. As the MBMS transmission is digital, it is proposed that the primary error measure for a radio network quality would be any of a Block Error rate or a Bit Error rate, typically detected by a cyclic redundancy check parity check, or error correction code calculation over a certain received data block. Other measures could of course be considered, such as interference level.

Such error rates would be easy to measure in a UE. The measurement could be done in the same way for a multitude of MBMS applications, and the measured entity can be mapped to user satisfaction or user experience.

Error measurements on higher level, such as the measurements defined in 3GPP TS 26.346, Multimedia Multicast/Broadcast Service (MBMS), protocols and codecs, could also be used. Preferably, to more easily be able to compare to measurements, the measured entity should be relative, e.g. the ratio of the media stream that could be properly reconstructed vs. not properly reconstructed during a certain time interval, e.g. the ratio of presentation media frames suffering from errors versus correctly reconstructed presentation media frames.

Such application level measurements would, more reliably than pure radio error rate, map to user satisfaction .The above kind of measurements are subsequently referred to as error-rate-measurements.

As the above measured entities are proposed to be relative, they are independent of session length, amount of received data etc, and thus different measurements can more easily be compared than absolute measurements.

Basic Measurements

It is proposed that it should be possible to do measurements of signal strength or received energy of known symbols, pilot symbols on the MBMS radio carrier or any entity that can be derived from these. The signal strength, received energy or derived entity could further be related to a reference, e.g. interference level, received noise energy etc. This kind of measurements is subsequently referred to as signal-strength measurements.

Such measurements would be easy to do in a UE. Many UEs would anyway need to do such measurements for mobility functionality etc. The measurement is completely independent of MBMS application, but provides good information on the basic radio conditions to enable root cause analysis of application level problems (that e.g. are detected by another measurement).

Such measurements can be done, on pilot channels, synchronization channels or system information broadcast channels, even when there are no MBMS transmissions ongoing. This give a possibility to verify and measure the Radio Access Network ability to operate, independent of application servers operational status, which would be convenient e.g. at initial installation scenarios.

It is further proposed that the measured entity in the signal strength measurement shall be divided into classes, and that the number of measurements done, or the amount of time where results maps to a certain QoS class shall be counted, to form class based counters that can be added together averaged for several UEs to form network level statistics indicators.

By this kind of measurement the results or "average" results from several UEs can easily be added together by adding the time or amount of measurements or fraction of time or amount of measurements each UE reported for every QoS Class, to form statistics measurement results for the whole network or a part of the network, with respect to the QoS Classes.

If the measurement result is requested immediately, the average QoS class of a few sampled frames could be reported.

In that way, the number of UEs reporting a certain QoS class could be summed or averaged to form QoS class metrics for the network. This could be particularly useful when the UE does the measurement on a test transmission and the User do not want to see the transmission. Also, this makes it possible to make a measurement with a short time span to minimise the impact on UE battery life.

All the measurements above are subsequently referred to as "QoS measurements".

MEASUREMENTS DURING MOBILITY From experience of wireless access systems in general, it can be assumed that the mobility procedures are the most sensitive ones regarding user-perceived quality.

Handovers, cell selections etc are done where the radio conditions are at their worst, and triggered by changes in radio conditions, and can easily involve data loss, or complete loss of session.

It is proposed that the above QoS measurements could be done at MBMS mobility, i.e. when the UE changes MBMS Cell, or changes MBMS Single-frequency-network

Area, whichever is applicable.

In this way, important information regarding possible root cause in the MBMS wireless network, of user-experienced problems can be collected.

It is proposed that the above QoS measurements could be done at UC mobility, for a MBMS MC network or for a UC network overlaid with a MBMS DC network, i.e. when the UE changes Cell.

In this way, important information regarding possible root cause in the radio environment of the wireless network, of user-experienced problems can be collected.

LOCATION MEASUREMENTS

The method according to the invention could in one embodiment include that the information includes any from the group consisting of: a location parameter, cell- beam id, cell id. Thus, it is proposed that the location of a UE could be measured and reported by the UE, which also could report other measurements. It is further

proposed that, in the post processing of data, QoS measurement result data could be grouped, summed or averaged according to location. This is needed order to locate problematic geographical areas.

It is proposed that it shall be possible for the network to configure the granularity and/or positioning mechanism of the location that is reported by the UE. This brings the possibility to first detect problems on a coarse level, using simple location mechanisms, and then (e.g. for a certain problematic area) the problem could be pinpointed to more specific areas. The possible alternative to always report position on finest granularity is most often not good, as the fine-granular position measurements, e.g. Assisted-GPS are associated with extensive UE processing and impact on battery or extensive signalling, or both. Particularly for UEs not currently receiving MBMS it would be desirable to minimise impact to UE battery life.

It is also proposed that information that is transmitted from the network can be used as location indication, e.g. cell id, cell portion id (cell beam id), location area id, routing area id, tracking area id, service area id, MBMS service area id, geographical position (e.g. lat, long) or logical position (at Shell gas-station no XX) of base station, base station id or similar. Such information could also be embedded in the session data or control stream, e.g. MBMS session identifier etc. Note that the base-station may be a regular MBMS base-station, or a UC base-station or a particular base-station used for positioning. This approach is very simple. It does not require any particular measurements. The UE just need to receive the information sent from the network.

It is further proposed that if the UE can receive different such information from different base stations of the network, the UE may report this received information from several base stations as location indications.

Also, if the UE can receive such information from several base-stations, the UE may also do signal strength measurements for those base-stations, and report both signal strengths and location information from those base-stations or order/filter the location information according to signal strength. These simple extensions of the simple mechanism above would provide extra positioning accuracy. The extra UE

implementation cost would be very low, as any UE would anyway need the capability of signal strength measurements for mobility.

The above simple mechanism and simple mechanism with extensions could be further extended by UE measuring roundtrip time to/form one or several base stations, or measuring phase difference of signals from different base stations (e.g. OTDO A). This would provide a further increase in positioning accuracy.

Positioning could be based on uplink measurements, e.g. UTDOA. In this case the network would have to correlate the UE location and the UE QoS measurements. This would provide good positioning accuracy, and would be particularly low-cost if such a positioning system exists already for other purposes.

Positioning could be done also by using satellite positioning systems, GPS, Glonass etc. This could be done with or without network provided assistance data. That would provide good positioning accuracy, and would be particularly low-cost if such a positioning system exists already for other purposes.

MEASUREMENT CONTROL It is proposed that the above QoS measurements could be configured by a management entity, which could belong to the network,

• to run for a certain time period.

• to run for multiple time periods, with specific interval.

• to run a quick on-demand measurement, i.e. just based on reception of a small amount of data.

• to be measured and/or reported only run if the UE is in a particular location.

In this way, it would be possible for the operator to tailor the measurements according to the particular use case, to optimize the UE load, UE battery life and load on the wireless interface for measurement reporting.

• By the possibility to run a measurement for a certain time period, the time could be limited to save resources, and the measurement could be limited to specifically interesting moments in time, e.g. when a test transmission is sent.

• By the possibility to run measurements for multiple periods with intervals, there is the possibility to have measurements going on for longer times with small resource consumption, e.g. UE battery life.

• By the possibility to do quick on-demand measurements, it would be possible to get a rough view of the network operation quickly, and with minimal UE resource consumption.

• By the possibility to have a measurement reported only if the UE is in a particular location, the load on the wireless interface could be reduced, by only including particularly interesting areas. » By the possibility to have a measurement executed only if the UE is in a particular location, the load on the UE would be decreased.

In particular, the various load reductions mentioned above would be particularly significant if the UE is not receiving MBMS.

TIME STAMPING AND TIMING

A measurement result could be associated with a time-stamp, which can be included in UE measurement reports. This makes it possible to correlate reported results with the time for the measurement, not needing to specify an exact time by measurement control, and also allow non-immediate reporting and allow that various intermediate post-processing systems stores the measurement results, while still maintaining the traceability to the time for the measurement, in a simple way.

For measurements that are done repeatedly, several times or in several time periods, the UE could report the time-period during which the measurements were done. Knowing the time when a measurement is done makes it possible to calculate the statistics metrics according to different time periods, e.g. some measurements might be especially interesting at telephony-busy-hour when radio interference is at its peak.

It is proposed that the applicable time intervals (start time and stop time), for time- stamping and for running/maintaining counters in the UE shall be configured by the network. In this way, it is possible to have all UEs report counters applicable to a particular time interval. This makes it possible to calculate statistics metrics for several UEs, on network level, according to different time periods, with network selected granularity.

UE MODEL SPECIFIC META DATA

It is proposed that the UE shall include UE equipment information in the measurement report. The equipment information could include vendor, model etc. The equipment information could be IMEI, or part thereof. This information could be included per specific request by the network. Thus, the post-processing system could calculate statistics metrics for different UE equipments, to identify equipment-specific problems.

Alternatively, the UE could include its identity, to identify itself to a system that has the equipment information, which then could supply the equipment information to be added in the statistics data reports sent to the O&M post processing systems. Possibly the UE identification method could require combination of information from several systems, e.g. Radio Access Network (RAN) converting a RAN specific UE identity into an identity known by the core network, which could subsequently be used etc. In this manner, the post-processing system could calculate statistics metrics for different UE equipments, to identify equipment-specific problems, without the need for the UE to expose equipment information every time it does a measurement report, which could be a security risk.

The concept of UE statistics data measurements could also be used for UC systems and services. Part of the measurements and their principles as defined here could be used also for UC systems and services.

ORDERING OF FORMING AND FEEDING BACK OF INFORMATION

In accordance with the method of the invention, there is a possibility for the forming and feeding back of information in the receiver or UE, to be done autonomously. For instance, the receiver could be pre-programmed to do such forming and feeding back of information.

There is also a possibility for ordering the receiver to do such forming and reporting. In one embodiment of the method of the invention, the forming and feeding back of information is ordered by an ordering entity via any communication means that can communicate with the at least one receiver. This any communication means could be

the different communications means. In that case, ordering could be initiated by paging the at least one receiver.

Another possibility is to use the terrestrial radio network as the any communication means. That is to use the network sending the multimedia service transmission as an ordering channel to the receiver.

For any of these ordering alternatives, the order could be addressed to a subset of the multiple receivers. This would be beneficial for instance if there is an interest of reports from a subset of the possible receivers. Such a subset could for instance be defined by any entity chosen from the group consisting of: number of receivers, geographical area of multiple receivers.

Any order as mentioned above could include ordering which different communication means to use for feeding back the information relevant for the multimedia service transmission intended for multiple receivers.

Similarly, the order could include ordering which management entity should receive the information relevant for the multimedia service transmission intended for multiple receivers.

Also, an order as mentioned above could include ordering which information to form in the at least one receiver. Such ordered information could e.g. be a position estimate for the at least one receiver with a required accuracy.

In case there are optional measurements and counters, or optional ways to perform / calculate the measurements and counters, or optional ways to report the results, a proposal is that the network shall control which options shall be used. If there are parameters for the control of these options, the network shall decide the settings of the parameters. The UE might propose options and settings and provide its capabilities to the network. By this approach, it is possible for the network operator to tailor the measurements and counters towards a specific use case, e.g. initial network deployment, continuous network monitoring etc. By this, it is possible for the operator to control the trade-off between good visibility and network load caused by reporting.

Thus, this makes it possible to control that the UE measurements and counters for statistics do not cause excessive network load, in all parts of the network.

It is possible for the network to control MBMS related UE measurements and counters by control information sent on the MBMS carrier.

In, particular, it should be possible for the network to control MBMS related UE measurements and counters by control information that is independent of the control information for the MBMS service or session. In particular, this should be possible by sending control information by regular control channels of this radio carrier or regular control channels for the MBMS service. In particular, these channels may be Common Control Channels, such as a broadcast control channel (3GPP BCCH) or a MBMS control channel (3GPP MCCH), or may be a dedicated control channel (3GPP DCCH). By this approach, all UEs that are receiving MBMS transmissions or are currently interested in such transmissions (e.g. monitoring MBMS control channels) can be reached, to configure and control measurements and counters that are applicable to them. By this approach, measurements can be requested on demand from UEs, e.g. based on radio interface troubleshooting demand, not associated to the actual MBMS session.

It is possible for the network to control MBMS related UE measurements and counters by control information sent on communication channels other than the MBMS carrier.

In particular, for the MBMS DC deployments, this should be possible by sending control information by radio carriers of an overlaid UC network. In particular if this network is either of GERAN, UTRAN, LTE, CDMA2000, AIE, WiFi, WiMAX.

In, particular, it should be possible for the network to control MBMS related UE measurements and counters by control information that is independent of the control information for the MBMS service or session. In particular, this is possible by sending control information by regular control channels of the UC radio carrier or regular control channels for a MC MBMS service on the UC carrier. In particular, these channels may be Common Control Channels, such as a broadcast control channel (3GPP BCCH) or a MBMS control channel (3GPP MCCH), or a dedicated control channel (3GPP DCCH). By this approach, also UEs that are not currently receiving MBMS transmissions or are currently interested

in such transmissions can be reached, to configure and control measurements and counters that are applicable to them. By this approach, it is possible to enable measurements and counters also in geographical areas where MBMS service is out of coverage or where MBMS service is malfunctioning. By this approach, it is possible to enable measurements and counters also when there are no users or UEs that are listening to MBMS or are interested in MBMS, e.g. based on test transmissions, or without test transmissions. In this way, useful data could be collected during initial deployments, when the number of active users is low, or during low traffic hours, e.g. in the middle of the night, e.g. to verify network operation right after a network reconfiguration or upgrade has been done.

It is possible to trigger measurements by Paging one or several UEs. Either all control information related to the requested measurement could be sent in the paging message, or the paging message would just trigger the UE to use any of the other mechanisms mentioned above to obtain full control information for a particular measurement. The UE would not need to continuously monitor various control channels just for the purpose to find the measurement control information, i.e. UE resource consumption (e.g. UE battery) could be reduced. The measurement control info would not need to be scheduled on such channels that the UE always regularly monitors, and thus the load on such channels could be avoided. E.g. if a UE camps on a UC carrier and the

MBMS measurement control information is transmitted on a MBMS DC, for UE load and UE battery consumption point of view it would be good to avoid that the UE continuously monitor the MBMS DC, especially for UEs that are not receiving MBMS.

The different communications means for feeding back the information to a management entity could according to one aspect of the method of the invention be a radio access network overlapping geographically with the terrestrial radio network. Examples of such a network are for instance any network from the group consisting of: GSM, WCDMA, CDMA2000, GERAN, UTRAN, 3GPP LTE, AIE, WiFi, WiMax.

For such a radio access network overlapping geographically with the terrestrial radio network, a transport mechanism of the radio access network could be used to transport the information. One example of such a mechanism is a. packet data transport

mechanism. Another example of such a transport mechanism is a messaging application.

Note that for statistics data / counters / measurements, the Radio Access Network is not the main recipient of the measurement results. Instead, the main recipient is an

O&M post-processing system and this system may or may not belong to the operator which requested measurement results to be sent. In fact in order to facilitate features such as infrastructure sharing, or standalone MBMS operator or commercial agreements between any mix of operator scenarios, it is necessary to have control over where measurement reports are to be sent.

To handle MBMS DC scenarios, the reporting mechanism is proposed to be possible through various UC Radio Access technologies e.g. GERAN, UTRAN, 3GPP LTE, WiMax etc.

Thus, in order for this to be practically possible, it is very important that the implementation impact in the Radio Access Network is minimal with respect to support for the UE statistics data measurement reporting.

Also, it is desirable to minimize the number of data conversions that are needed, for the O&M statistics post processing system to be able to process the measurement data from the UEs.

It is proposed that the data transport mechanism for measurement reporting, when different transport mechanisms are allowed/possible, and the associated parameters for the transport mechanism shall be configured by the network, and information on this configuration shall be sent to the UE, either when a UE statistics measurement is requested, using the same mechanism as for measurement control, or another mechanism, e.g. System Information broadcast (3GPP BCCH), or MBMS control channel (3GPP MCCH), or - for measurements. Possibly the reporting transport mechanism configurations could be different for different measurements. In this manner, there would be a flexibility to have different reporting mechanisms for the same set of MBMS statistics data measurements. This would be useful in the scenario

of MBMS DC overlaid with a UC network, where the UC networks can be different and support different mechanisms, or are optimized for different mechanisms.

In particular, it is proposed that it shall be possible that the address(es) of the receiver(s) of the different measurement results are configured by the network, e.g. IP address(es), application port (if not fixed), URL/URIs, a B-side telephone number, shall be configured, and allowed to be different per requested measurement. A benefit with this is that there would be a flexibility for different kind of measurements to be directed to different servers, e.g. session-related vs. non-session related measurements might have completely different targets, one reported to a home network, the other reported to a visited network, or one reported to a troubleshooting server/terminal, and the other reported to a server for statistics data post processing.

In particular, it is proposed that is shall be possible that when the measurement reports are requested the system requesting the measurement reports can specify to which PLMN the measurement report should be sent. This may take the form of a list of preferred PLMNs. This would facilitate different operator commercial agreements. Allowing for example infrastructure sharing agreements between different operator scenarios, for example, allowing a MBMS dedicated operator to request mobiles to make measurements reports and report them via the unicast operators network.

In particular, in addition to the PLMN indication a preferred radio access technology can be specified. In addition to the PLMN list another list of preferred technologies. This would allow further control (where for example there is dual coverage scenarios) of where the mobile sends the measurement reports thus allowing to favour certain access technologies where there may be either optimised channels or available resources for these purposes.

In particular, it is proposed that any UC radio bearer supporting packet data transmission could be used for statistics measurement reporting. The preferred channel or bearer or bearer type should be configured by the network. NOTE, that the prior art solution [2], allows general IP bearers. By this principle, the need to redesign UC technologies to support particular optimized bearers and reporting mechanisms for UE statistics data measurements could be avoided. Most UC technologies will

support data bearers efficiently. Some UC radio technologies support low-overhead common-channel type of bearers that are especially suited for short data transmissions. Some UC radio technologies support low-overhead UE initiated-setup bearers that are especially suited for short data transmissions. In particular, it would be easy to use a File Transfer Protocol using a TCP/IP transport protocol. In particular, if the data is in a special format, a format-optimized transport protocol, such as the XCAP (for XML) protocol could be used.

Alternatively, it is proposed that any messaging application could be used for statistics measurement reporting, e.g. SMS, MMS or similar. By this principle, the need to redesign UC technologies to support particular optimized bearers and reporting mechanisms for UE statistics data measurements could be avoided. Non interactive messaging applications would have approximately the same response time requirements as MBMS statistics data measurements, and would already be designed to use the most optimal radio bearers for short data transmissions in the various UC technologies.

It is proposed that the measurement results of the UE should be reported in a UC- radio-technology-agnostic format, e.g. a compressed data file, compressed XML data, packed ASN.1 etc. Note that this characteristic is fulfilled also by prior art [2]. By this principle, the UE application (and the network statistics data application) could be simplified in a UC-heterogeneous environment. Other applications It could be noted that all applications involving UEs that are involved in or related to multicast or broadcast services, and that require the UEs to respond to the network, involve similar requirements.

As an alternative for a different communications means for feeding back the information to a management entity, a fixed network would be possible to use. Such a fixed network could for instance be the internet.

In accordance with any earlier embodiment of the method according to the invention, the adjustment of the multimedia service transmission could include reconfiguring radio network parameters for the radio network for multimedia service transmission.

In accordance with any earlier embodiment of the method according to the invention, there is a possibility for the terrestrial radio network, sending a multimedia service transmission, to be operating in a downlink mode only. An example of such a downlink only mode is a single frequency mode operating network (SFN) such that a plurality of radio transmitters are operating in synchronism, allowing the at least one receiver to receive the transmission from multiple transmitters simultaneously.

In a real world implementation of the method of the invention, there would be a need for a receiver, or user equipment (UE) having a receiver, that is adapted to handle the different steps of said method. Such a receiver for reception of a multimedia service transmission intended for multiple receivers over a terrestrial radio network, wherein the multimedia service transmission intended for multiple receivers being sent from a radio transmitter, would be distinguished by that: - the receiver being adapted to form information relevant for the multimedia service transmission intended for multiple receivers,

- the receiver being adapted to feed back the information to a management entity using a different communications means, so as to allow an adjustment of the multimedia service transmission intended for multiple receivers in respect of said information on the multimedia service transmission intended for multiple receivers. For any of the different embodiments of the method according to the invention, such a receiver would be modified accordingly with the necessary features in order to be able to execute said method.

EXAMPLES

Examples illustrating some principles of the invention will now be given.

It is proposed that the UE shall do statistics related measurements and maintain counters that are related to the user experience and the reception of MBMS transmission, and the UE shall report the results to the network.

As shown in Figure 1 , the expected end receiver of data derived from the proposed UE statistics counters and measurements is not Radio Nodes in the wireless network,

but instead a human operator, and possibly support tools used by the human operator (this is contrary to current UE measurements in mobile systems).

Elaborations of figure 1 1. The UE is within expected coverage of MBMS. The UE may be receiving

MBMS service, or the UE might not be receiving MBMS service. 2. The UE performs statistics measurements and maintain statistics counters with respect to MBMS reception, MBMS service and User experience of MBMS service. 3. The UE reports the results of the statistics measurements and counters to the network.

4. In the network, there may be several steps of data post processing and data conversion. The Radio Access network may be involved in post processing and data conversion to make it possible to optimize reporting by compression techniques that are specific to the Radio Access Technology.

5. The result of post processing is presented to a human operator, possibly in the form of statistical indicators where results of measurements from many UEs are combined, possibly also combined with results reported from other nodes, possibly combined over certain time periods. Results might also be converted into alarms in the case of drastic changes.

6. Other results of statistics post processing, e.g. more detailed geographical information might be input to support tools, that the operator could use for network tuning and troubleshooting.

Reporting Principles

It is proposed that it shall be possible for the UE to use a communication mechanism that is separate from MBMS radio bearers or separate from the MBMS system, to report the result of statistics measurements and counters. In particular, it is proposed that a UC system overlaid with a MBMS system can be used for reporting of results. This is especially interesting if the MBMS system is a

DC system.

In particular, for a MC system, it is proposed that the UE could use communication mechanisms related to general control of UE, or communication mechanisms related to UC and/or UC services for the reporting of results.

In addition, it should be possible for the UE to use an MBMS-specific UL communication mechanism, to report the result of statistics measurements and counters.

Figure 2: The communication mechanism that UE uses to report results can be different from the MBMS system or different from the MBMS communication channels, or related to the MBMS communication channels. Except step 3 (a,b,c), where detail and alternatives has been added, figure 2 shows the same as figure 1.

Elaborations:

3a. UE could use another, Unicast capable, wireless network, e.g. on another radio carrier for reporting. This alternative would be especially attractive when a DC system is overlaid with a UC network.

3b. If supported by the MBMS system (a MC system), UE could use UL resources on the same carrier as the MBMS system. These UL resources could be either a. A UE control channel b. A UC data transport channel, not related to MBMS c. An UL transport or control channel related to MBMS. 3c. Another, not specified mechanism, e.g. UE sends report when plugged in to internet by any means of connectivity.

Control Principles

In case there are optional measurements and counters, or optional ways to perform / calculate the measurements and counters, or optional ways to report the results, it is proposed that the network shall control which options shall be used. If there are parameters for the control of these options, the network shall decide the settings of the parameters. The UE might propose options and settings and provide its capabilities to the network.

It should be possible for the network to control MBMS related UE measurements and counters by control information sent on the MBMS carrier.

In particular, it should be possible for the network to control MBMS related UE measurements and counters by control information that is independent of the control information for the MBMS service or session.

In particular, this should be possible by sending control information by regular control channels of this radio carrier or regular control channels for the MBMS service. In particular, these channels may be Common Control Channels, such as a broadcast control channel (3GPP BCCH) or a MBMS control channel (3GPP MCCH), or may be a dedicated control channel (3GPP DCCH).

It should be possible for the network to control MBMS related UE measurements and counters by control information sent on communication channels other than the MBMS carrier.

In particular, it should be possible for the network to control MBMS related UE measurements and counters by control information that is independent of the control information for the MBMS service or session.

In particular, for the MBMS DC deployments, this should be possible by sending control information by radio carriers of an overlaid UC network. In particular if this network is either of GERAN, UTRAN, LTE, CDMA2000, AIE, WiFi, WiMAX. In particular, this should be possible by sending control information by regular control channels of the UC radio carrier or regular control channels for a MC MBMS service on the UC carrier. In particular, these channels may be Common Control Channels, such as a broadcast control channel (3GPP BCCH) or a MBMS control channel (3GPP MCCH), or a dedicated control channel (3GPP DCCH).

It should be possible to trigger measurements by Paging or Notification to one or several UEs. Either all control information related to the requested measurement could be sent in the paging/notification message, or the paging/notification message would just trigger the UE to use any of the other mechanisms mentioned above to obtain full control information for a particular measurement.

Figure 3: Measurement Control could be done is several ways. 1. Operator Configures UE statistics measurement options and parameters by an

O&M system. Operator could also select the control method, 3a or 3b, depending on use case.

2. O&M system distributes this control info to radio access network.

3 a. For use cases that involves only UEs that monitors MBMS channels already, or when the MBMS network is a MC network that supports also UC, UE statistics measurement options and parameters could be sent to UE by the MBMS wireless network.

In particular, this control info could be sent to UE by: a. A Common Control channel related to the Radio Access Technology, e.g. the broadcast control channel (3GPP: BCCH). b. A MBMS Control Channel (3GPP: MCCH). c. A UE dedicated control channel (3GPP: DCCH), only for MC network configuration. d. Application level control channel carried e.g. by UC Packet Bearer or SMS cell broadcast, only for MC network configuration. e. A Paging/Notification message, or a combination of a paging/notification message and any of the methods 3a:a-d.

3b. For MBMS DC systems, for those use cases that involves UEs that do not currently monitor MBMS channels, e.g. those that are out-of-coverage or those that are currently not interested (maybe there is only test transmissions ongoing, or no transmissions), UE statistics measurement options and parameters would need to be partially of fully sent to UE by non-MBMS network, e.g. an overlaid UC network.

In particular, this control info could be sent to UE by: a. A UC Common Control channel related to the Radio Access Technology, e.g. the broadcast control channel (3GPP: BCCH). b. A MC MBMS Control Channel, if the UC network supports MBMS MC (3GPP: MCCH). c. A UC UE dedicated control channel (3GPP: DCCH) d. Application level control channel carried e.g. by UC Packet Bearer or SMS cell broadcast. e. A Paging/Notification message, or a combination of a paging/notification message and any of the methods 3a:a-d, 3b:a-d.

In addition to statistics data measurements, any interactive TV applications e.g. voting, and also UE counting for bearer reconfigurations for MBMS could be handled in similar ways.

SOME CONCLUDING OBSERVATIONS Other advantages of the present invention include:

-Troubleshooting of the Radio Access Network and has been considered. There are means to correlate radio conditions to application layer quality problems. There are means to correlate application layer problems with certain geographical areas. Also mobiles that not actively receive MBMS transmission can be asked to report statistics measurement results.

-Load Control according to the invention considers load control of the radio interface. Furthermore, load control in the statistics prior art is adaptive w.r.t. the number of UEs in the network.

-There is a possibility to request immediate or on-demand measurements for troubleshooting.