GB2510152A

GB2510152A - Reporting a status to a network when transmission parameter thresholds are reached

Info

Publication number: GB2510152A
Application number: GB1301362.8A
Authority: GB
Inventors: Brian Alexander Martin; Keiichi Kubota
Original assignee: Broadcom Corp
Current assignee: Broadcom International Ltd; Broadcom Corp
Priority date: 2013-01-25
Filing date: 2013-01-25
Publication date: 2014-07-30
Also published as: GB201301362D0

Abstract

Methods for reporting a status to a network are described. First and second thresholds for a transmission parameter, such as transmission buffer occupancy or TCTV, are configured, with the second being greater than the first. If the first threshold is exceeded, the status is reported, and a timer is started. If the second threshold is exceeded and the timer is not active or active due to a report triggered by the first threshold, the status is reported, and the timer is started or re-started. In another aspect, first and second timers are included. When the second threshold is exceeded, the second timer is started. The second timer is stopped if the parameter falls below the first threshold. If the second timer expires, and the first timer is not active or active due to a report triggered by the first threshold, the status is reported, and the first timer is started or re-started. Alternatively, first and second timers are started when the parameter rises above the first and second thresholds respectively, and stopped when it falls below the respective threshold. When the second timer expires, or the first timer expires when the second is not active, the status is reported. These methods may be useful for a UE in a CELL-FACH state.

Description

APPARATUS AND METHOD OF REPORTING STATUS TO A NETWORK

Technical Field

The present invention relates to an apparatus configured to report its status to the network in response to certain events and a corresponding method. The invention can be applied to mobile devices and devices configured to operate in a Universal Mobile Telecommunications System (TiNTS).

Background

3GPP TS 25.331 (version 11.3.0 Release 11, November 2012) defines the protocol specification for Radio Resource Control (RRC) in a User Equipment (UE) operating in the Universal Mobile Telecommunications System (UMTS).

The system currently in use in UMTS provides for a number of defined activity states for the user equipment, including an Idle state, a CELL PCH/TJRA PCH (paging channel) state, a CELL FACH (forward access channel) state, and a CELL_DCH (dedicated channel) state. In the Idle state, the user equipment does not have an RRC (Radio Resource Control) connection and is the state having the lowest power consumption. In the CELL PCH/URA PCH state, the user equipment is again in a low power consumption state as it only periodically looks for incoming paging messages, and in this state does have a RRC connection.

However, the user equipment needs to be in the CELL_EACH or CELL_DCH state in order to be able to perform both transmission and reception of data (including in particular "user" data, as opposed to data relating to control or management of the device and its network connection, etc. for example). In the CELL DCH state, a dedicated physical channel is allocated to the user equipment. In the CELL_FACH state, the user equipment shares the physical channel with other user equipment, though nevertheless may have a dedicated logical channel. As is well understood, a logical channel in this context is an information stream dedicated to the transfer of a specific type of information over the radio interface and corresponds to an individual sigual which can be separated or isolated from an aggregate of signals which occupy the same physical bandwidth or channel. CELL_FACH can be regarded as a transition state between the idle/CELL PCH/URA PCH and CELL_DCH states.

3GPP IS 25.331 (version 11.3.0, release 11) defines a reporting mechanism which allows a IJE to send measurement reports while operating in CELL FACH state. One event that can trigger these reports is when the total of all transmission buffers for a channel (the Transmission Channel Total Volume or TCTV) exceeds a threshold defined by the network during the set up procedure for CELL FACH state.

More specifically, these measurement reports can be sent in CELL FACH state with an event ID of "4a" and can be triggered in a number of ways with reference to the TCTV and the threshold defined. On receipt of a measurement report for event 4a from a TiE the network may reconfigure the UE to be in CELL DCH state so that data can be transmitted at a higher rate.

The triggering of an event 4a measurement report (hereafter "4a report") can operate in an event driven manner, for example when the TCTV rises above a threshold. For a further report to be generated, the TCTV must then fall below the threshold and rise above it again. 3GPP TS25.331 also defines optional timers which alter the conditions and frequency at which 4a reports are sent. These timers are "Time To Trigger" (ITT) and "Pending Time After Trigger" (PTAT).

TTT defines a period for which the TCTV must remain above the threshold before a 4a report is issued. It can be used to add hysteresis to the reporting. When the TCTV rises above the threshold, the TTT timer is started. Starting a timer can also be referred to as activating the timer. If TCTV drops below the threshold while the TTT timer is running, the TTT timer is stopped and no report is sent. If the TTT timer runs to expiry a 4a report is sent.

PTAT defines a period after a 4a report is sent in which no further reports should be sent. The PTAT timer is started after a 4a report is sent. Should a 4a report be triggered while PTAT is running, no report is sent. On expiry of PTAT a further 4a report is sent if the TCTV is still above the threshold, or TTT is started if it is configured. In this way PTAT sets a minimum time between 4a reports in CELL FACH state.

Summary

According to a first exemplary embodiment of the present invention, there is provided An apparatus comprising a transmitter configured to transmit data and a processor. The processor is configured to report the status of the apparatus to a network by: configuring a timer that is active for a predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the first threshold and provided that the timer is not active, reporting the status of the apparatus to the network and starting the timer; and responsive to the transmission parameter rising above the second threshold and provided that the timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the timer.

According to another exemplary embodiment, there is provided n apparatus comprising a transmitter configured to transmit data; and a processor. The processor is configured to report the status of the apparatus to a network by: configuring a first timer that is active for a first predetermined time after it is started, a second timer that is active for a second predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the second threshold, starting or restarting the second timer; responsive to the transmission parameter falling below the first threshold, stopping the second timer if it is active; and responsive to the second timer expiring and provided that the first timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the first timer.

According to a further exemplary embodiment, there is provided an apparatus comprising a transmitter configured to transmit data and a processor. The processor is configured to report the status of the apparatus to a network by: configuring a first timer that is active for a predetermined time after it is started, a second timer that is active for the predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to the transmission parameter rising above a first threshold starting the first timer; responsive to the transmission parameter rising above a second threshold, starting the second timer; responsive to the transmission parameter falling below the second threshold, stopping the second timer; responsive to the transmission parameter falling below the first threshold, stopping the first timer; responsive to expiry of the first timer and provided that the second timer is not active, reporting the status of the apparatus to the network; and responsive to expiry of the second timer, reporting the status of the apparatus to the network.

According to another exemplary embodiment, there is provided a method of reporting a status of an apparatus to a network, the method comprising, at the apparatus: configuring a timer that is active for a predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the first threshold and provided that the timer is not active, reporting the status of the apparatus to the network and starting the timer; and responsive to the transmission parameter rising above the second threshold and provided that the timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the timer.

According to another exemplary embodiment, there is provided A method of reporting thc status of an apparatus to a nctwork, the method comprising, at the apparatus: configuring a first timer that is active for a first predetermined time after it is started, a second timer that is active for a second predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the second threshold, starting or restarting the second timer; responsive to the transmission parameter falling below the first threshold, stopping the second timer if it is active; and responsive to the second timer expiring and provided that the first timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the transmission buffer to the network and starting or restarting the first timer.

According to another exemplary embodiment, there is provided a method of reporting the status of an apparatus to a network, the method comprising, at the apparatus: configuring a first timer that is active for a predetermined time after it is started, a second timer that is active for the predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to the transmission parameter rising above a first threshold starting the first timer; responsive to the transmission parameter rising above a second threshold, starting the second timer; responsive to the transmission parameter falling below the second threshold, stopping the second timer; responsive to the transmission parameter falling below the first threshold, stopping the first timer; responsive to expiry of the first timer and provided that the second timer is not active, reporting the status of the apparatus to the network; and responsive to expiry of the second timer, reporting the status of the apparatus to the network.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 shows a diagrammatic representation of a communications system in which embodiments of the invention can operate; Figure 2 shows a diagrammatic representation of a radio interface protocol architecture that can be used in embodiments of the invention; Figure 3 shows a timing diagram for reporting status showing a delay when two thresholds and a pending time after trigger timer is configured; Figure 4 shows a timing diagram for reporting status showing a delay when two thresholds and a pending time after trigger timer and a time to trigger timer are configured; Figure 5 shows a timing diagram for reporting status showing a situation where a report of status may imply inaccurate information about the sending apparatus when there are two thresholds; Figure 6 depicts a flow chart of the processing that can be implemented in response to the TCTV rising above a second threshold in an example of the invention; and Figure 7 depicts a flow chart of the processing that can be implemented for a first TTT timer when two TTT timers arc configured in an example of the invention.

Detailed Description

"Wireless devices" include in general any device capable of connecting wirclcssly to a nctwork, and includes in particular mobile dcviccs including mobilc or cell phones (including so-called "smart phones"), personal digital assistants, pagers, tablet and laptop computers, content-consumption or generation devices (for music andlor video for example), data cards, USB dongles, etc., as well as fixed or more static devices, such as personal computers, game consoles and other generally static entertainment devices, various other domestic and non-domestic machines and devices, etc. The term "user equipment" or lIE is often used to refer to wireless devices in general, and particularly mobile wireless devices.

The terms "transmitter" and "receiver" arc also used herein and arc to be construed broadly to include the whole of a device that is transmitting/receiving wireless signals as well as only particular components of a device that are concerned with transmitting/receiving wireless signals or causing or leading to the transmission/reception of wireless signals.

Reference will sometimes be made in this specification to "network", "network control apparatus" and "base station". In this respect, it will be understood that the "network control apparatus" is the overall apparatus that provides for general management and control of the network and connected devices. Such apparatus may in practice be constituted by several discrete pieces of equipment. As a particular example in the context of UMTS (Universal Mobile Telecommunications System), the network control apparatus may be constituted by for example a so-called Radio Network Controller operating in conjunction with one or more Node Bs (which, in many respects, can be regarded as "base stations"). As another example, LTE (Long Term Evolution) makes use of a so-called evolved Node B (eNB) where the RF transceiver and resource management/control functions arc combined into a single entity. The term "base station" is used in this specification to include a "traditional" base station, a Node B, an evolved Node B (eNB), or any other access point to a network, unless the context requires otherwise. Moreover for convenience and by convention, the terms "network", "network control apparatus" and "base station" will often be used interchangeably, depending on the context.

Figure 1 depicts a diagrammatic representation of a communications system in which embodiments of the invention may be used. Figure 1 shows schematically a user cquipmcnt or wireless device, in this case in the form of a mobile phone/smartphone 1. The user equipment I contains the necessary radio module 2, processor(s) and memory/memories 3, antenna 4, etc. to enable wireless communication with the network. The user equipment I in use is in communication with a radio mast 5. As a particular example in the context of UMTS (Universal Mobile Telecommunications System), there may be a network control apparatus 6 (which may be constituted by for example a so-called Radio Network Controller) operating in conjunction with one or more Node Bs (which, in many respects, can be regarded as "base stations"). As another example, LTE (Long Term Evolution) makes use of a so-called evolved Node B (eNB) where the RF transceiver and resource management'control frmnctions are combined into a single entity. The term "base station" is used in this specification to include a "traditional" base station, a Node B, an evolved Node B (eNB), or any other access point to a network, unless the context requires otherwise. The network control apparatus 6 (of whatever type) may have its own processor(s) 7 and memory/memories 8, etc. Figure 2 shows schematically an example of the radio interface protocol architecture applicable for a TIE 1 in for example UMTS and E-TJTRAN. A similar "layer" architecture is used in other wireless systems. lii overview and in general terms, there is a physical layer Li 10, a data link layer L2 20 and a network layer L3 30. The physical layer Li 10 offers information transfer services to MAC and higher layers and defines the relationship between the liE I and the wireless transmission medium. The data link layer L2 20 is split into following sublayers: Medium Access Control (MAC) 21, Radio Link Control (RLC) 22, Packet Data Convergence Protocol (PDCP) 23 and Broadeast/Multicast Control (BMC) 24. The network layer L3 and the RLC 22 are divided into a Control (C-) plane 40 (which in essence deals with control signals) and a User (U-) plane 41 (which in essence deals with user-generated data traffic). In the C-plane 40, the network layer L3 30 is partitioned into sublayers where the lowest sublayer, denoted as Radio Resource Control (RRC) 31, interfaces with the data link layer L2 20 and ultimately terminates in the radio access network.

3GPP TS25.331 version 11.3.0 Release 11 (incorporated herein by reference for all purposes) defines the protocols governing the operation of the RRC. It includes logic in scctions 14.4.2 and 14.4.3 for the event based triggering of measurement reports with an event ID of 4a (hereafter 4a reports') based on a single threshold when a UE is operating in CELL FACH state. The threshold applies to the value of the Transmission Channel Total Volume (TCTV) which is equal to the sum of the buffer occupancy for all logical channels mapped onto a transport channel.

Events are triggered by the TCTV being above the threshold on channel set up or modification or the TCTV subsequently rising above the threshold. On receipt of a 4a report the network may reconfigure the TIE to operate in a different state, such as the CELL DCII state or a CELL FACI-1 state with a different Transmission Time Interval. Two timers can also be configured, a Time To Trigger (TTT) and a Pending Timer After Trigger (PTAT) as discussed above.

Release 11 of 3GPP allows a TiE to be configured with either a lOms Transmission Time Interval (TTI) or a 2ms TTI when operating in CELL FACH state. The TTI changes the rate at which data can be transmitted: a smaller TTI means that data can be transmitted at a higher rate. Therefore, the UE can transmit at a higher data rate for a 2ms TTI than for a lOms TTI CELL FACH.

The operation of the threshold used to trigger 4a reports defined in 3GPP TS 25.33 1 is not ideally suited when a TiE operates according to Release 11 and can be configured in either 2ms or lOms TTI in CELL FACH state. This is due to the fact that each TTI will require a different threshold for optimal operation. For example, a threshold optimized for lOms TTI will generally be too low for 2ms TTI because the higher transmission rate possible under 2ms TTI allows a buffer to be emptied more quickly.

A first threshold and a second threshold can be used to trigger 4a reports when a UE is configured with two or more different TTIs in CELL FACH state. For example, considering the 2ms TTI and lOms III that are possible in CELL FACH state under Release 11 of 3GPP, the first threshold can be configured at a suitable value for a lOms TTI to 2ms TTI transition and the second threshold can be configured at a suitable value for a 2ms TTI to CELL DCH transition. The second threshold will be higher than the first threshold because the greater transmission rate possible with 2ms TTT means buffers can be emptied more quickly so a higher threshold can be tolerated. Other embodiments can configure the first threshold and second threshold to values suitable for the particular state transition governed by the transmission parameter. For example, the first threshold can be configured to a value which is suitable for a lOms TTI to CELL DCH transition in a legacy IJE (one not compatible with Release 11 or higher of 3GPP). The first threshold may also beset to a value suitable for both the lOms TTI to 2ms TTI transition for 3GPP Release 11 compatible UEs and the lOms TTI to CELL DCH transition for legacy UEs.

When there are two thresholds, one way to adapt the existing event triggered logic for 4a reports in 3GPP TS 25.331 is to speciT that reports can be triggered by the TCTV rising above a second threshold as well as above the first threshold. While this will work when neither TTT nor PTAT timers are configured, the event driven logic when PTAT and/or TTT timers are configured can create situations where a 4a report is delayed longer than desirable, or where a 4a report is sent at an inappropriate time. Embodiments of the invention address at least one of these situations to provide more reliable sending of status reports, such as 4a reports, when two thresholds are configured either within a single measurement event or using multiple measurement events for a transmission parameter, such as TCTV, and one or more timers are configured, such as one or more PTAT and TTT timers.

In a first exemplary embodiment, an apparatus comprises a transmitter and a processor. For example, the transmitter and the processor can be in a UE configured to operate in a IJMTS network, such as that described above with reference to Figures 1 and 2. The processor is configured to report the status of the apparatus when a transmission parameter rises above a second threshold, which is higher than a first threshold, provided that a timer is not active or is active duo to reporting triggered by the transmission parameter above the first threshold. This embodiment allows a timer, which normally prevents reporting of status while it is active, to be overridden in the case that a second threshold is passed while the timer is running for the first threshold. In such an apparatus, the reporting of the status can be a Traffic Volume Measurement Report for event 4a while the apparatus is operating in CELL FACH state; the transmission parameter can be the TCTV and the timer is a PTAT timer for event 4a.

This embodiment allows a report that the transmission paramctcr has passed through the second threshold to be sent sooner rather than later. Indeed, it is advantageous to signal to the network as soon as possible that the transmissioll parameter has reached the second threshold. For example, if the TCTV reaches the second threshold, it would bc advantagcous for the network to be able to cause thc UE to change from CELL FACH state to CELL DCH state in order that a configuration with higher data throughput is achieved as soon as possible.

It has been identified that the operation of a timer which prevents further reports being sent while it is running, such as is the case with the aforementioned PTAT timer, can result in a delay to the reporting of the TCTV passing through the second threshold. This scenario is depicted in Figure 3, which depicts the TCTV 52 against time for a UB without the logic of this embodiment in a UIVITS network when two thresholds are defined and only a flAT timer is configured (TTT is not used).

As the TCTV rises above the first threshold 54, a 4a report is sent at time ti. The PTAT timer is then started. In response to the first 4a report the network does not take action to change the UE into CELL DCFI state, perhaps because it knows the liE is configurcd in 2ms TTI CELL_FACH so the first thrcshold 54 is not appropriatc to change it to CELL DCH. Meanwhile, the TCTV contiimes to rise, passing the second threshold 56 at time t2; however, no 4a report is given at time t2 because PTAT is still ruiming. PTAT expires at time t3, at which point a 4a report is sent.

The 4a report that the TCTV is over the second threshold 56 is therefore delayed by a time t3-t2. This means that a 4a report for the second threshold can never be issued more quickly than the value of PTAT following the TCTV rising through the first threshold 54. A potential change to CELL_DCH state is delayed. PTAT can be configured to be as long as 16 seconds (3GPP TS 25.331, section 10.3.7.72).

Therefore, the delay in reporting can be significant, up to almost 16 seconds if TCTV is increasing very quickly. A delay of this length is noticeable to the user and can contribute to a poor user experience.

When a UE is configured in accordance with the embodiment described above, this problem can be avoided because the timer can be ovenidden and a report sent when the transmission parameter passes through the second threshold whfle the timcr is activc duc to reporting the transmission parameter passing through the first threshold.

The processor can be configured, responsive to the timer expiring at the end of the predetermined time and the transmission parameter being at or above the first threshold, to report the status of the apparatus to the network and start the timer. This allows for repeated status reports each time the timer expires provided that the transmission parameter is above the first threshold.

The starting the timer can comprise setting an indication whether the timer was started because a report was triggered due to the first threshold or due to the second threshold. This provides a simple way for the apparatus to determine whether the timer is running due to a report above the first threshold or above the second threshold. For example a flag or other variable can be set if a report was sent as a result of the transmission parameter exceeding the first threshold.

In another exemplary embodiment, the processor is configured to start or restart a second timer when a transmission parameter passes a second threshold, which is higher than a first threshold. For example, the transmission parameter can be the TCTV and the second timer can be a TTT timer. Responsive to the second timer expiring, provided that a first timer is not active or the first timer is active due to reporting the status triggered by the transmission parameter above the first threshold, the apparatus reports its status to the network and starts the first timer. For example, the first timer can be a timer which normally prevents reports being sent while it is active, such a PTAT timer. This embodiment allows the first timer to be overridden if it is active due reporting passing the first threshold when the second timer expires following passing the second threshold. The benefits of this embodiment can be explained with reference to Figure 4, which shows the steps performed by a UE without the logic of this embodiment, and where the UE is configured in CELL FACH state with two thresholds defined. Both a PTAT timer and a TTT timer are configured. In this case the TCTV 52 passing through the first threshold 54 starts the TTT timer which expires at time t4. A 4a report is then generated at time t4 and the PTAT timer started. Meanwhile the TCTV continues to rise and passes the second threshold 56 at time tS so the TTT timer is started. The TTT timer expires at time t6 but no 4a report is sent because thc PTAT timcr is still running. The PTAT timer finally expires at time t7 and the TTT timer is started. The TTT timer expires at time t8 and a further 4a report is generated. The 4a report that the TCTV is over the second threshold is delayed by a time t8-t6. As with the case for Figure 3, a 4a report for passing the second threshold 56 cannot be issued more quickly following a 4a report for passing the first threshold 54 than the value of PTAT, which can be as long as 16 seconds, giving a poor user experience.

When a UB is configured in accordance with the embodiment described above, this problem can be avoided by overriding the first timer (for example a PTAT timer) if it is active due to the transmission parameter passing the first threshold when a second timer expires (for example a TTT timer) which was started due to passing the second threshold.

The processor of the apparatus can be further configured to report the status of the apparatus to a network by, responsive to the first timer expiring and provided that the transmission parameter is at or above the first threshold, starting the second timer.

This allows for repeated status reports on while the transmission parameter is above the first threshold. A status report is sent and the first timer started again if the second timer runs until it expires.

The processor can be further configured to report the status of the apparatus to a network by: responsive to the transmission parameter rising above the first threshold, starting the second timer and setting an indication that the second timer was started due to the first threshold; and responsive to the second timer expiring with the indication that the second timer was started due to passing the first threshold, and provided that the first timer is not active, reporting the status of the apparatus to the network and starting the first timer. Thus, when the indication that the second timer was started due to the first threshold is present, the first timer is not overridden. This allows a single second timer to be used for both passing the first threshold and passing the second threshold, with the action taken on expiry of the second timer being appropriate to what triggered it. The processor can then be further configured to report the status of the apparatus to a network by: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the sccond timer with thc indication that the second timcr was started due to the first threshold if the transmission parameter is above the first threshold but below the second threshold. Further embodiments may use an indication that the second timer was started due to the second threshold.

The processor can be further configured to report the status of the apparatus to a network by: configuring a third timer that is active for the second predetermined time after it is started; responsive to the transmission buffer rising above the first threshold, starting the third timer; responsive to the transmission buffer falling below the first threshold, stopping the third timer; and responsive to the third timer expiring and provided that the first timer is not active and the second timer is not active, reporting the status of the apparatus to the network and starting the first timer. In embodiments for use in UIVITS, the third timer can be a TTT timer for event 4a specific to passing the first threshold and the second timer can then be a TTT timer for event 4a specific to passing the second threshold. This allows the apparatus to suppress a report for passing the first threshold (by the third timer expiring) if the second timer is running, as is the case if the transmission parameter has passed the second threshold. In some embodiments, the processor can be further configured, responsive to the transmission parameter falling below the second threshold, to stop the second timer.

It is desirable to ensure that a report of the status based on the transmission parameter reflects the configuration of the timers as accurately as possible. When a status report is given on the expiry of a timer, such as a TTT timer when a UE is configured to operate in CELL FACH state in a UMTS network, the status report that is generated uses the value transmission parameter, such as the TCTV, at the time the timer expires. It has been identified that with a rapidly rising transmission parameter, a timer that has started due to passing the first threshold can result in a report with a value above the second threshold. This can imply to the network, erroneously, that the TCTV has been above the second threshold for the whole of the timer duration, which is not the case. This situation is depicted in Figure 5, which depicts the TCTV 58 against time for a UE without the logic of this embodiment which is configured in CELL_FACH state with two thresholds defined. Only the TTT timer is configured (no PTAT timer is configured). As the TCTV 58 rises above the first threshold 4, the TTT timer is started at time tS. Meanwhile, the TCTV 58 continues to rise, passing the second threshold 6 at time t9 while the TTT timer is still running. The TTT timer expires at time t10, generating a 4a report with the value of the TCTV at that time, which is above the second threshold 56. However this report is misleading to the network because the TCTV has only been above the second threshold 56 for a time tlO-t9, not the frill value of TTT. TTT can be as long as 5 seconds (3GPP TS 25.33 1, section 10.3.7.64) so the TCTV does not have to be rising particularly quickly for a misleading report to issue.

When a UE is configured in accordance with the embodiment described above, this problem can be avoided by the provision of a timer for the first threshold (the third timer) and a timer for the second threshold (the second timer). A report due to the timer for the first threshold expiring is suppressed if the timer for the second threshold is running.

The processor can be further configured to report the status of the apparatus to a network by: responsive to expiry of the third timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped or if the second timer is subsequently stopped and the transmission parameter is above the first threshold. This provides a mechanism to report the status if reporting due to the third timer is suppressed (in expectation of a report on expiry of the second timer) but the second timer is subsequently stopped. Stopping a timer is not the same as it expiring. A timer expires when it has run for its configured time. An active timer (a timer that is running) can bc stopped at any time. For example, the second timer can be stopped when the transmission parameter falls below the second threshold. When a timer is stopped no further action is taken due that timer.

In embodiments with the third timer, the processor can be further configured to report the status of the apparatus to a network by: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the third timer if the transmission parameter is above the first threshold and below the second threshold. This allows a report of status to be generated each time thc first timcr expires if thc transmission paramctcr is abovc thc first or sccond threshold.

In another embodiment, an apparatus comprises a transmitter and a processor.

For example the apparatus can be a liE with a transmitter and processor configured to operate in a UMTS network such as described above with reference to Figures 1 and 2. The processor is configured to report the status of the apparatus to a network when a first timer expires provided that a second timer is not active. The first timer and the second timer can be TTT timers. The first timer is started responsive to a transmitter parameter rising above a first threshold and the second timer is started by the transmission parameter rising above a second threshold, which is eater than the first threshold. The transmission parameter can be the TCTV when the UE is configured in CELL FACH state. This embodiments suppresses reports due to passing the first threshold when a report due to passing the second threshold is imminent (because the second timer is running). It improves performance in the situation discussed with reference to Figure 5 above.

The processor can be further configured to report the status of the apparatus to a network by: responsive to expiry of the first timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped or if the second timer is subsequently stopped and the transmission parameter is above the first threshold. This ensures that a report due to passing the first threshold is still sent if the second timer is subsequently stopped.

Further embodiments of the invention provide methods and computer programs for reporting the status of an apparatus to a network. These methods and computer programs correspond to the configuration of the processor as described above.

Examples of the various embodiments described above will now be described with reference to Figures 6 and 7. Figures 6 and 7 depict flow charts of the processes that can be implemented in embodiments to provide status reports. In these examples an apparatus is configured to operate in a UMTS network and specificafly to an apparatus configured in CELL FACH state and sending measurement reports for event 4a based on the TCTV. The apparatus is configured to send event driven measurement reports and follows the logic set out in 3GPP TS 25.331 except as set out below.

Figure 6 depicts the processing carried out in an apparatus of an example to determine whether to send a measurement report under event 4a in which a Pending Time After Trigger (PTAT) timer can be overridden to provide a status report when the TCTV passes a second threshold if the previous report was sent due to the TCTV being above a first threshold but below the second threshold. The thresholds are used to trigger sending a measurement report to the network, the network may use the report to reconfigure the apparatus. In this example the first threshold is configured to a value suitable for I Oms TTI and the second threshold is configured to a value suitable for 2ms TTI for compatibility with 30FF TS 25.331 Release 11. Other example may use thresholds configured with values appropriate to other transmission states, the thresholds may also vary depending on the characteristics of each particular network.

In these examples, the existing logic of 3GPP TS 25.331 Release 11 sections 14.4.2 and 14.4.3 is used with respect to the first threshold except as described below.

In summary, the existing logic of 3GPP TS25.331 means that a measurement report is triggered if the TCTV is above the first threshold on channel set up or modification or if the TCTV subsequently rises above the first threshold. If a PTAT timer is configured, it is started when a measurement report is sent. If a TTT timer is configured, it is started when a report is triggered and stopped if the TCTV falls below the first threshold while it is running. When a TTT timer is configured, reports are sent on the expiry of the timer provided that the PTAT timer is not active (i.e. not running). When a PTAT timer is configured a report is triggered if, on expiry of the PTAT timer, the TCTV is above the first threshold.

In this embodiment the existing logic of TS 25.33 is modified to include a flag, variable or other information element associated with the PTAT timer. This is used to indicate the threshold that triggered the report that started the PTAT timer.

For example, a flag can be set to indicate triggering due to the first threshold.

Triggcring due to the second threshold can then be implied by flag not being set.

Alternatively a variable or information element can identify the threshold that triggered the report, for example by having a value identifying the threshold that triggered the report.

The example depicted in Figure 6 corresponds to a scenario in which the TCTV rises above the second threshold. The steps responsively performed are described in terms of a sequential flow chart for ease of explanation, so that the interaction between events can be understood more clearly. However, the steps may be performed in response to changes in the value of the TCTV and expiry of the timers.

First, at step 100, the TCTV rises above the second threshold to start the processing. Next at step 102, it is checked whether an Information Element (IE) "Time to trigger" is present. This IE is present ifa TTT timer has been configured. If no IE "Time to Trigger" is present, processing continues to step 112. Otherwise the TTT timer is started, or restarted if it is already running, at step 104.

At step 106 it is determined whether the TTT timer has expired, if it has execution proceeds to step 112. Otherwise it is determined whether the TCTV has fallen below the first threshold at step 108. If the TCTV has fallen below the first threshold the TTT timer is stopped and processing ends without further action at step 110. The processing of steps 106, 108 and 110 can be event driven in some embodiments. In an event driven logic, processing moves to step 112 on expiry of the TTT and the TCTV falling below the first threshold stops the TTT in step 110.

At step 112, it is determined whether a "Pending Time after Trigger" (PTAT) timer associated with event 4a is active. The PTAT timer is active if it is running, i.e. if a PTAT timer has been configured, started and has not yet expired. If no PTAT timer is active execution proceeds to step 116, otherwise execution proceeds to step 114.

If a PTAT timer is active it is determined at step 114 whether it is active because of a report sent due to the first threshold. If this is true (for example if a flag, variable or other element associated with the PTAT timer indicates it was started due to the TCTV being above the first threshold) then processing proceeds to step 116, otherwise processing ends at step 118.

At step 116 a measurement report for event 4a is prepared and sent to the network. Thus, the determination at step 114 enables a measurement report for event 4a to be sent for passing the second threshold even if the PTAT timer is running due to a measurement report for the TCTV passing the first threshold.

Next, at step 120, a check is made whether the IE "Pending Time after Trigger" is included. This IF is included if a PTAT timer is configured. If the IE "Pending Time after Trigger" is included, execution proceeds to step 122. At step 122 the PTAT timer is either started or restarted with an indication of the threshold that triggered the report after which the PTAT timer was started. For example, a flag, variable or other element may be set as appropriate. Restarting the PTAT timer ensures that if it is already running, any further reports due to the PTAT timer expiring will occur the full configured time of the PTAT after the report in step 116.

Execution then ends at step 118.

In examples using event driven processing, the determinations of step 112, 114 and 120 can be carried out responsive to the TTT timer expiring (if a TTT timer is configured) or the TCTV rising above the second threshold (if a TTT timer is not configured).

Referring now to Figure 7, processing in an example in which two TTT timers are configured will be described. Figure 7 depicts the processing carried out to determine whether to send a measurement report under event 4a from an apparatus operating in CELL FACH state in a UMTS network when two TTT timers are associated with respective thresholds in the event 4a reporting logic. A first TTT timer is associated with the first threshold and a second TTT timer is associated with the second threshold. Reporting due the first ITT timer expiring is suppressed if the second TTT timer is active.

The processing of this example is the samc as that set out in 3GPP TS 25.331 except as described below. In summary, the second TTT timer is started if the TCTV is above the second threshold on channel set up or modification or if the TCTV subsequently rises above the second threshold. The second TTT timer is stopped if the TCTV falls below the second threshold. On expiry of the second TTT timer a measurement report under event 4a is sent provided that the PTAT timer, if configured, is not active. If a PTAT timer is configured no measurement reports are sent while it is active. The PTAT timer is started when a measurement report under event 4a is sent. On expiry of the PTAT timer either the first TTT timer is started (if the TCTV is above the first threshold and below the second threshold), the second TTT timer is started (if the TCTV is at or above the second threshold) or no action is taken (all other situations).

Processing using the first ITT timer will now be described with reference to Figure 7. The first TTT timer is started due to the TCTV being above the first threshold but below the second threshold on channel set up or modification or subsequently rising above the first threshold. This is indicated by step 200 in Figure 7. Next, at step 202 the first TTT timer is started, It is then checked at step 204 whether the first TTT timer has expired. If it has, execution proceeds to step 212.

Otherwise, at step 206 it is checked whether the TCTV is still above the first threshold. If the TCTV is still above the first threshold, processing returns to step 204 to check again for expiry of the first TTT timer. Otherwise, the first TTT timer is stopped at step 208 and processing ends at step 210.

In an event driven example, expiry of the first TTT timer results in execution proceeding to step 212. The TCTV falling below the first threshold results in the first TTT timer being stopped at step 208.

At step 212 it is determined whether the second ITT timer is active. The second TTT timer is active if it has been configured and is currently running. If the second TTT timer is not active execution proceeds to step 218. Otherwise, execution proceeds to step 214 where the second TTT timer is monitored for whether it expires or stops. Processing proceeds to step 216 when the second TTT timer expires or stops and it is determined whether the second TTT timer expired or stopped. If the second TTT timer expired proccssing ends at step 210. Otherwise, if the second TTT timer was stopped, processing continues to step 218. This ensures that a report due the first TTT timer is suppressed if the second TTT timer is running. However the check at step 216 enables a report to still be sent if the second TTT timer is subsequently stopped.

At step 218 it is determined whether a PTAT timer is active. If a PTAT timer is active processing ends at step 210. Otherwise, processing proceeds to step 220 where a measurement report under event 4a for the first threshold is sent and the PTAT timer is started, if configured, before processing ends at step 210.

Some embodiments can include an optional check that the TCTV is still above the first threshold before executing step 220.

In a further example, the processing of the Figure 6 and Figure 7 examples above is combined. For example, the processing of Figure 6 can be used for the second TTT timer in the example of Figure 7 in response to the transmission parameter rising above the second threshold.

Although at least some aspects of the embodiments described herein with reference to the drawings comprise computer processes performed in processing systems or processors, the invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice.

The program may be in the form of non-transitory source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other non-transitory form suitable for use in the implementation of processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a solid-state drive (SSD) or other semiconductor-based RAM; a ROM, for example a CD ROM or a semiconductor ROM; a magnetic recording medium, for example a floppy disk or hard disk; optical memory devices in general; etc. It will be understood that the processor or processing system or circuitry refened to herein may in practice be provided by a single chip or integrated circuit or plural chips or integrated circuits, optionally provided as a chipset, an application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), digital signal processor (DSP), etc. The chip or chips may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry, which are configurable so as to operate in accordance with the exemplary embodiments. In this regard, the exemplary embodiments may be implemented at least in part by computer software stored in (non-transitory) memory and executable by the processor, or by hardware, or by a combination of tangibly stored software and hardware (and tangibly stored firmware).

The above embodiments are to be understood as illustrative examples of the invention. It is to be understood that any featnre described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

Claims 1. An apparatus comprising: a transmitter configured to transmit data; and a processor configured to report a status of the apparatus to a network by: configuring a timer that is active for a predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than thc first threshold; responsive to a transmission parameter rising above the first threshold and provided that the timer is not active, reporting the status of the apparatus to the network and starting the timer; responsive to the transmission parameter rising above the second threshold and provided that the timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the timer.
2. The apparatus of claim 1, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to the timer expiring at the end of the predetermined time and the transmission parameter being at or above the first threshold, reporting the status of the apparatus to the network and starting the timer.
3. The apparatus of claim I or 2, wherein the starting the timer comprises setting an indication whether the timer was started because a report was triggered due to the first threshold or due to the second threshold.
4. An apparatus comprising: a transmitter configured to transmit data; and a processor configured to report a status of the apparatus to a network by: configuring a first timer that is active for a first predetermined time after it is started, a second timer that is active for a second predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is grcater than the first threshold; responsive to a transmission parameter rising above the second threshold, starting or restarting the second timer; responsive to the transmission parameter falling below the first threshold, stopping the second timer if it is active; and responsive to the second timer expiring and provided that the first timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the first timer.
5. The apparatus of claim 4, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to the first timer expiring and provided that the transmission parameter is at or above the first threshold, starting the second timer.
6. The apparatus of claim 4 or 5, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to the transmission parameter rising above the first threshold, starting the second timer and setting an indication that the second timer was started due to the first threshold; and responsive to the second timer expiring with the indication that the second timer was started due to passing the first threshold, and provided that the first timer is not active, reporting the status of the apparatus to the network and starting the first timer.
7. The apparatus of claim 6, further comprising wherein the processor is further configured to report the status of the apparatus to a network by: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the second timer with the indication that the second timer was started due to the first threshold if the transmission parameter is above the first threshold but below the second threshold.
8. The apparatus of claim 4, wherein the processor is further configured to report the status of the apparatus to a network by: configuring a third timer that is active for the second predeteniiined time after it is started; responsive to the transmission buffer rising above the first threshold, starting the third timer; responsive to the transmission buffer falling below the first threshold, stopping the third timer; and responsive to the third timer expiring and provided that the first timer is not active and the second timer is not active, reporting the status of the apparatus to the network and starting the first timer.
9. The apparatus of claim 8, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to expiry of the third timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped.
10. The apparatus of claim 8, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to expiry of the third timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped and the transmission parameter is above the first threshold
11. Thc apparatus of claim 8, 9 or 10, wherein the processor is thrther configured to report the status of the apparatus to a network by: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the third timer if the transmission parameter is above the first threshold and below the second threshold.
12. An apparatus comprising: a transmitter configured to transmit data; and a processor configured to report a status of the apparatus to a network by: configuring a first timer that is active for a predetermined time after it is started, a second timer that is active for the predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to the transmission parameter rising above a first threshold starting the first timer; responsive to the transmission parameter rising above a second threshold, starting the second timer; responsive to the transmission parameter falling below the second threshold, stopping the second timer; responsive to the transmission parameter falling below the first threshold, stopping the first timer; responsive to expiry of the first timer and provided that the second timer is not active, reporting the status of the apparatus to the network; and responsive to expiry of the second timer, reporting the status of the apparatus to the network.
13. The apparatus of claim 12, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to expiry of the first timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped.
14. The apparatus of claim 12, wherein the processor is further configured to report the status of the apparatus to a network by: responsive to expiry of the first timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped and the transmission parameter is above the first threshold.
15. An apparatus according to any one of the preceding claims configured to operate in a Universal Mobile Telecommunications System.
16. A wireless device including the apparatus of any one of the preceding claims.
17. A method of reporting a status of an apparatus to a network, the method comprising, at the apparatus: configuring a timer that is active for a predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the first threshold and provided that the timer is not active, reporting the status of the apparatus to the network and starting the timer; responsive to the transmission parameter rising above the second threshold and provided that the timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the apparatus to the network and starting or restarting the timer.
18. The method of claim 17, further comprising: responsive to the timer expiring at the end of the predetermined time and the transmission parameter being at or above the first threshold, reporting the status of the apparatus to the network and starting the timer.
19. The method of claim 17 or 18, wherein the starting the timer comprises setting an indication whether the timer was started because a report was triggered due to the first threshold or due to the second threshold.
20. A method of reporting a status of an apparatus to a network, the method comprising, at the apparatus: configuring a first timer that is active for a first predetermined time after it is started, a second timer that is active for a second predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to a transmission parameter rising above the second threshold, starting or restarting the second timer; responsive to the transmission parameter falling below the first threshold, stopping the second timer if it is active; and responsive to the second timer expiring and provided that the first timer is not active or is active due to reporting triggered by the transmission parameter above the first threshold, reporting the status of the transmission buffer to the network and starting or restarting the first timer.
21. The method of claim 20, further comprising: responsive to the first timer expiring and provided that the transmission parameter is at or above the first threshold, starting the second timer.
22. The method of claim 20, further comprising: responsive to the transmission parameter rising above the first threshold, starting the second timer and setting an indication that the second timer was started due to the first threshold; and responsive to the second timer expiring with the indication that the second timer was started due to passing the first threshold, and provided that the first timer is not active, reporting the status of the apparatus to the network and starting the first timer.
23. The method of claim 22, further comprising: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the second timer with the indication that the second timer was started due to the first threshold if the transmission parameter is above the first threshold but below the second threshold.
24. The method of claim 20, further comprising: configuring a third timer that is active for the second predetermined time after it is started; responsive to the transmission buffer rising above the first threshold, starting the third timer; responsive to the transmission buffer falling below the first threshold, stopping the third timer; and responsive to the third timer expiring and provided that the first timer is not active and the second timer is not active, reporting the status of the apparatus to the network and starting the first timer.
25. The method of claim 24, further comprising: responsive to expiry of the third timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped.
26. The method of claim 24, further comprising: responsive to expiry of the third timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped and the transmission parameter is above the first threshold
27. The method of claim 24, 25 or 26, further comprising: responsive to the first timer expiring, starting the second timer if the transmission parameter is above the second threshold or starting the third timer if the transmission parameter is above the first threshold and below the second threshold.
28. A method of reporting a status of an apparatus to a network, the method comprising, at the apparatus: configuring a first timer that is active for a predetermined time after it is started, a second timer that is active for the predetermined time after it is started, a first threshold for a transmission parameter and a second threshold for the transmission parameter, wherein the second threshold is greater than the first threshold; responsive to the transmission parameter rising above a first threshold starting the first timer; responsive to the transmission parameter rising above a second threshold, starting the second timer; responsive to the transmission parameter falling below the second threshold, stopping the second timer; responsive to the transmission parameter falling below the first threshold, stopping the first timer; responsive to expiry of the first timer and provided that the second timer is not active, reporting the status of the apparatus to the network; and responsive to expiry of the second timer, reporting the status of the apparatus to the network.
29. The method of claim 28, further comprising: responsive to expiry of the first timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequently stopped.
30. The method of claim 28, further comprising responsive to expiry of the first timer, monitoring the second timer if the second timer is active and reporting the status of the apparatus to the network if the second timer is subsequendy stopped and the transmission parameter is above the first threshold.