GB2506839A

GB2506839A - Management of dormancy timers in wireless communications

Info

Publication number: GB2506839A
Application number: GB1214343.4A
Authority: GB
Inventors: Brian Alexander Martin; Keiichi Kubota
Original assignee: Broadcom Corp
Current assignee: Broadcom International Ltd; Broadcom Corp
Priority date: 2012-08-10
Filing date: 2012-08-10
Publication date: 2014-04-16
Also published as: WO2014024175A3; WO2014024175A2; GB201214343D0

Abstract

A mobile terminal and base station may transmit and receive data from one another via a wireless network. When the mobile terminal is preparing to end a data transmission operation, the terminal may communicate this to the base station via an end of data signal. When the base station receives the communication and completes transmission to the mobile terminal, the base station may send a signal to the mobile terminal indicating that the mobile terminal should proceed directly to a dormancy (DRX) state, bypassing one or more inactivity timers. Direct transition to a DRX state without waiting for an inactivity timer to expire leads to improved power conservation. In one embodiment the mobile station may unilaterally enter a DRX state without performing the handshake process. The mobile station may transition to a longer DRX cycle bypassing the inactivity timer and an intermediate shorter DRX cycle.

Description

Managing Timers

Technical Field

The present invention relates generally to wireless communications, and, more particularly, but not exclusively, to management of dormancy timers in wireless communications.

Background

It is increasingly common for smartphones, laptops, and other devices to contain communications interfaces that are capable of interacting with wireless data services such as 30, WiMax, and Long Term Evolution (LTE) networks.

Proliferation of these devices has also lead to development of novel applications and usage patterns that leverages the "always on" nature of the wireless data networks.

However, use of these technologies includes certain tradeoffs. For example, mobile terminals transmitting on the same network share bands of the signal spectrum, requiring careful scheduling to avoid contention for resources. These terminals are frequently powered by rechargeable batteries, such that frequent transmission and reception operations may dramatically reduce the operational life of the device before it must be recharged. As such, wireless protocols are often developed to minimize the risk of channel contention and unnecessary transmission and reception operations.

One problem that has been observed is the best manner to manage tradeoff'; between allowing a terminal to go dormant while still minimizing latency. By allowing a terminal to go dormant between transmissions, battery power may be conserved because the terminal is not actively transmitting or receiving data.

However, it may take time to recover from the dormant state, thus resulting in increased latency when transmission and/or reception are resumed. As such, efficient operation of the terminal seeks to maximize dormancy time while minimizing the frequency with which the terminal must recover from the dormant state. Different transmission pattems may result in different optimal dormancy patterns.

One method that has been employed for implementing dormancy settings for mobile terminals is the use of two inactivity timers. As the terminal sends and receives data, a first inactivity timer may be initialized after a particular period without any data transmission or reception. If no data is sent or received for the duration of the first inactivity timer, the mobile terminal may enter a first dormailcy state during which the mobile terminal goes dormant for a short period of time and then checks for new transmission or reception operations after the short period of time. If the terminal detects a data transmission or reception, it may return to an activc statc.

When the mobile terminal enters the first dormancy state, it may initialize a second inactivity timer. If the mobile terminal still does not detect any activity by the time the second inactivity timer expires, the mobile terminal may enter a second dormancy state. The second dormancy state may typically include a longer dormancy period before detecting new data transmissions (e.g., a longer "wake up" interval).

This allows the mobile terminal to be dormant for a longer period of time, thus leading to power savings. However, a longer period between checks for new data transmissions also rcsults in a longcr latency whcn a new transmission is reccivcd.

Configuration of the two timers in this manner serves to minimize delay by allowing the device to first wake up more frequently in the event the next transmission closely follows a first transmission (e.g., the data transfer is "bursty"), while allowing for a longer dormancy period after it is apparent that the data transmission has completed.

Examples of this dormancy processing mechanism are described in, for example, the

specification 25.331 subclausc 8.1.14.2.

However, in order to reach the long dormancy period (and thus maximum battery power saving), the first dormancy timer must expire. As such, at the end of a data transmission, the mobile terminal may spend time on the "short" dormancy period, using battery life even though the transmission has concluded. Particularly in the case of frequent, small data transmissions, waiting for both the first and second inactivity timers to expirc may cause the mobile terminal to consume morc powcr than the data transmission itself. For example, the small data transmission may wake up thc tcrminal from the second dormancy statc for a bricf transfer opcration, but the terminal will not bc ablc to rcturn to thc power saving mode of thc sccond dormancy state irntil both inactivity timers expire.

Sum mary A method, apparatus and computer program are therefore provided according to embodiments of the present invention in order to manage dormancy timers for a mobile terminal communicating on a wireless network. In this regard, the method, apparatus, and computer program of an example embodiment may utilize a mobile terminal to communicate with a wireless station. The mobile terminal and wireless station may transmit and receive data from one another via a wireless network. When the mobile terminal is prepared to end a data transmission operation, the terminal may communicate as such as the wireless station via an end of data signal. When the wireless station receives the communication and completes transmission to the mobile terminal, the wireless station may send a signal to the mobile terminal indicating that the mobile terminal should proceed directly to a second dormancy state, bypassing one or more inactivity timers.

In accordance with a first aspect of the present invention, there is provided a method of managing dormancy timers in wireless communications, the method comprising: determining that a mobile terminal has completed a data transfer operation; causing the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receiving a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy signal, causing, using a processor, the mobile terminal to enter at least one dormant state, wherein in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given period of time elapses.

In accordance with a second aspect of the present invention, there is provided apparatus for use in managing dormancy timers in wireless communications, the apparatus comprising a processing system adapted to cause the apparatus at least to: determine that a mobile terminal has completed a data transfer operation; cause the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receive a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy signal, enter at least one dormant state, wherein when the apparatus is in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given period of time elapses.

In accordance with a third aspect of the present invention, there is provided a computer program adapted to perform a method of managing dormancy timers in wireless communications, the method comprising: determining that a mobile terminal has completed a data transfer operation; causing the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receiving a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy signal, causing the mobile terminal to enter at least one dormant state, wherein in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given period of time elapses.

Embodiments may comprise a computer program product comprising a non-transitory computer-readable storage medium having computer readable instructions stored thereon, the computer readable instructions being executable by a computerized device to cause the computerised device to perform the method of the first aspect of the present invention.

Additional embodiments of the invention may include an apparatus for managing dormancy timers. The apparatus may include processing means for determining that a mobile terminal has completed a data transfer operation, processing means for causing the mobile terminal to send an end of data signal in response to completion of the data transfer operation, communications means for receiving a dormancy signal in response to the completion of the data transfer operation, and processing means for causing the mobile terminal to enter a dormant state in response to receiving the dormancy signal.

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

Having thus described certain embodiments of the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: Figure 1 is a block diagram of an apparatus that may be specifically configured in accordance with an embodiment of the present invention; Figure 2 is a schematic diagram of an example mobile terminal in communication with a wireless station in accordance with an embodiment of the present invention; Figure 3 is a block diagram of a message flow between a mobile terminal and a wireless station to transmit dormancy signal in accordance with an embodiment of the present invention; and Figure 4 is a flow diagram depicting an example of a method for processing a dormancy signal in accordance with an embodiment of the present invention.

Detailed Description

Some embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown, Indeed, various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. As used herein, the terms "data," "content," "information," and similar terms may be used interchangeably to refer to data capable of being transmitted, received and/or stored in accordance with embodiments of the present invention. Thus, use of any such terms should not be taken to limit the spirit and scope of embodiments of the present invention.

Additionally, as used herein, the term circuitry' refers to (a) hardware-only circuit implementations (e.g., implementations in analog circuitry and!or digital circuitry); (b) combinations of circuits and computer program product(s) comprising software and/or firmware instructions stored on one or more computer readable memories that work together to cause an apparatus to perform one or more functions described herein; and c) circuits, such as, for example, a processing system or microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation even if the software or firmware is not physically present.

This definition of circuitry' applies to all uses of this term herein, including in any claims. As a further example, as used herein, the term circuitry' also includes an implementation comprising a processing system or one or more processors and/or portion(s) thereof and accompanying software and/or firmware. As another example, the term circuitry' as used herein also includes, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cclhdar network device, other network device, and!or other computing device.

As defined herein, a "computer-readable storage medium," which refers to a non-transitory physical storage medium (e.g., volatile or non-volatile memory device), can be differentiated from a "computer-readable transmission medium," which refers to an electromagnetic signal.

A method, apparatus and computer program are provided in accordance with embodiments of the present invention in order to manage dormancy operations for a mobile terminal in a wireless network. In this regard, a method, apparatus and computer program according to embodiments may operate to enable communications between a mobile terminal and a wireless station. When the mobile terminal ceases data transmission operations, the mobile terminal may indicate as such to the wireless station via an end of data signal. In response to the end of data signal, the wireless station may send a dormancy signal to the mobile terminal instructing the mobile terminal to enter a particular dormancy mode, thus enabling the mobile terminal to transition directly to a frill dormancy mode without waiting for the expiration of one or more inactivity timers. The signal may be transmitted to the mobile terminal as part of scheduling information (e.g., a High Speed Shared Control Channel (HS-SCCH) message, as a Medium Access Control (MAC) or Radio Link Control (RLC) header element, as a Packet Data Convergence Protocol (PDCP) header element, or as a MAC control element. Transitioning directly to a dormancy mode at the termination of the transmission advantageously allows for improved control of when the device enters dormancy, thus leading to a conservation of device power.

The system of an embodiment of the present invention may include an apparatus 100 as generally described below in conjunction with Figure 1 for performing one or more of the operations set forth in Figures 2-4 and also described below. The apparatus will be described in terms of a mobile terminal as an example, but the apparatus 100 may also be embodied in another type of computing device, either mobile or fixed, such as a computer workstation, a personal computer, a laptop, a cellular phone, or a smart phone. In this embodiment, the mobile terminal may be in communication with a display and/or a data network, either directly, such as via a wireless or wireline connection, or indirectly via one or more intermediate computing devices. In this regard, the display and the mobile terminal may be parts of the same system in some embodiments. However, the apparatus 100 may alternatively be embodied by another computing device that is in communication with the display and the mobile terminal, such as via a wireless connection, a wircline connection or the like. For example, the apparatus may be a mobile telephone, a personal digital assistant (PDA), a pager, a laptop computer, a tablet computer, a data card, a USB dongle, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices or combinations thereof It should also be noted that while Figure 1 illustrates one example of a configuration of an apparatus 100 for managing dormancy timers, numerous other configurations may also be used to implement other embodiments of the present invention. As such, in some embodiments, although devices or elements are shown as being in communication with each other, hereinafter such devices or elements should be considered to be capable of being embodied within the same device or element and thus, devices or elements shown in communication should be understood to alternatively be portions of the same device or element.

Referring now to Figure 1, the apparatus 100 for managing dormancy operations in accordance with embodiments may include or otherwise be in communication with one or more of a processing system or processor 102, a memory or memory device 104, a communication interface 106, a user interface 108, a camera 110 and a sensor 112. In some embodiments, the processing system or processor (and/or co-processors or any other processing circuitry assisting or otherwise associated with the processor) may be in communication with the memory device via a bus for passing information among components of the apparatus. The memory device may include, for example, a non-transitory memory, such as one or more volatile and/or non-volatile memories. In other words, for example, the memory device may be an electronic storage device (e.g., a computer readable storage medium) comprising gates configured to store data (e.g., bits) that may be retrievable by a machine (e.g., a computing device like the processor). The memory device may be configured to store information, data, content, applications, instruetiolls, or the like for enabling the apparatus to carry out various functions in accordance with an embodiment of the present invention. For example, the memory device could be configured to buffer input data for processing by the processor. Additionally or altcrnativcly, thc memory devicc could bc configurcd to storc instructions for execution by the processor.

In some embodiments, the apparatus 100 may be embodied as a chip or chip set. In other words, the apparatus may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus may therefore, in some cases, be configured to implement an cmbodimcnt of the present invdiltion on a singlc chip or as a single "systcm on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

The processing system or processor 102 may be embodied in a number of different ways. For example, the processor may be embodied as one or more of various hardware processing means such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other processing circuitry including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. As such, in some embodiments, the processor may include one or more processing cores configured to perform independently. A multi-core proccssor may cnablc multiprocessing within a single physical package. Additionally or alternatively, the processor may include one or morc proccssors configured in tandcm via thc bus to enablc independent cxecution of instructions, pipclining and/or multithrcading.

In an example embodiment, the processor 102 may be configured to execute instructions stored in the memory device 104 or otherwise accessible to the processor.

Alternatively or additionally, the processor may be configured to execute hard coded functionality. As such, whether configured by hardware or software methods, or by a combination thereof, the processor may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA or the like, the processor may be specifically configured hardware for conducting the operations described herein.

Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the algorithms and/or operations described herein whcn the instructions are executed. However, in some cases, the processor may be a processor of a specific device configured to employ an embodiment of the present invention by frirther configuration of the processor by instructions for performing the algorithms and/or operations described herein. The processor may include, among other things, a clock, an arithmetic logic unit (ALIJ) and logic gates configured to support operation of the processor.

Meanwhile, the communication interface 106 may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or module in communication with the apparatus 100, such as by supporting communications with a display and/or a mobile terminal. In this regard, the communication interface may include, for example, an antenna (or multiple antennas) and supporting hardware and/or software for enabling communications with a wireless communication network. Additionally or alternatively, the communication interface may include the circuitry for interacting with the antenna(s) to cause transmission of signals via the antenna(s) or to handle receipt of signals received via the antenna(s). In some environments, the communication interface may alternatively or also support wired communication. As such, for example, the communication interface may include a communication modem and/or other hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB) or other mechanisms. The communication interface 106 may serve to couple the apparatus 100 to a cellular network, such as a network operating according to a 3G or Long Term Evolution (LTE) protocol.

The apparatus 100 may include a user interface 108 that may, in turn, be in communication with the processor 102 to provide output to the user and, in some embodiments, to receive an indication of a user input. For example, the user interface may include a display and, in some embodiments, may also include a keyboard, a mouse, a joystick, a touch screen, touch areas, soft keys, a microphone, a speaker, or other input/output mechanisms. In one embodiment, the display of the apparatus may be embodied by a liquid crystal display (LCD) screen presented on one surface of the mobile terminal. The processor 102 may comprise user interface circuitry configured to control at least some functions of one or more user interface elements such as a display and, in some embodiments, a speakcr, ringer, microphone and/or the like. The processor 102 and/or user interfacc circuitry comprising the processor 102 may be configured to control one or more functions of one or more user interface elements through computer program instructions (e.g., software and/or firmware) stored on a memory accessible to the processor (e.g., memory 104, and/or the like).

In some embodiments, the apparatus 100 may include an image capturing clement, such as a camera 110, video and/or audio module, in communication with the processor 102. The image capturing element may be any means for capturing an image, video and/or audio for storage, display or transmission. For example, in an example embodiment in which the image capturing element is a camera, the camera may include a digital camera capable of forming a digital image file from a captured image. A_s such, the camera may include all hardware (for example, a lens or other optical component(s), image sensor, image signal processor, and/or the like) and software necessary for creating a digital image file from a captured image.

Alternatively, the camera may include only the hardware needed to view an image, while a memory device 104 of the apparatus stores instructions for execution by the processor in the form of software necessary to create a digital image file from a captured image. In an embodiment, the camera 110 may further include a processing clement such as a co-processor which assists the processor in processing image data and an encoder and/or decoder for compressing and/or decompressing image data.

The encoder and/or decoder may encode and/or decode according to, for example, a joint photographic experts group (JPEG) standard, a moving picture experts group (MPEG) standard, or other format.

As shown in Figure 1, the apparatus 100 may also include one or more sensors 112, such as a location information receiver (e.g., a global positioning system (GPS) receiver), an accelerometer, a gyroscope, a compass, or the like, that may be in communication with the processor 102 and may be configured to determine the location of thc apparatus and to dctcct changes in motion and/or orientation of the apparatus.

The method, apparatus 100 and computer program product may now be described in conjunction with the operations illustrated in Figures 2-4. In this regard, the apparatus may include means, such as the processor 102, the communications interface 106, or the like, for managing dormancy operations. Data transmissions may occur between a mobile terminal and a wireless station, and, during or at termination of these data transmissions, a dormancy signal may be received at the mobile terminal from the wireless station. In some embodiments, the processor 102 may include and/or may execute an application for management of network operations, such as a network protocol stack, to receive a signal from a remote node of a network (e.g., a wireless station located at a cellular tower) to instruct the mobile terminal to enter a dormant state. In some embodiments, the processor 102 may cause the mobile terminal to enter the dormant state in response to receiving the dormancy signal. For example, a processing means, such as the processor 102, may instruct a communications means, such as the communications interface 106 to transition from a continuous data receive state to a dormant state upon receipt of the signal from the remote node of the network. Although the processor 102 is described as a single element, the processor 102 may also be implemented as one or more applications executing on one or more processors including, for example, a dedicated network processor, in communication with one another.

Figure 2 is a schematic diagram of an example mobile terminal in communication with a wireless station in accordance with an example embodiment of the present invention. Figure 2 depicts a wireless network 200 including a wireless station 202 in communication with a mobile terminal 204. The wireless network 200 may represent a single "cell" of a cellular network operated by a cellular provider.

The wireless station 202 may be a tower or set of towers for providing coverage to the cell of the network. The wireless network 200 may be provided according to one or more wireless protocols, such as 3G or LTE. Examples of wireless stations may include, but are not limited to, 3G "Node B" or "Radio Network Controller" nodes, or LTE "Enhanced Node B" (eNodeB) nodes.

The mobile terminal 204 and the wireless station 202 may communicate data over various frequencies of the spectrum. Communications may be enabled between these devices according to various scheduling methods, such as time division multiple access (TDMA) or code division multiple access (CDMA). The mobile terminal 204 may employ various methods of conserving device power, such as by attempting to minimize data transmission and reception operations. In order to efficiently manage thcsc operations, the devicc may cmploy onc or morc timcrs to managc dcvice dormancy states. For example, as described above, the mobile terminal may include three operational states: a continuous reception state, a first dormancy state, and a second dormancy state. When in the continuous reception state, the mobile terminal 204 may be actively sending and receiving data, such that new data received from the wireless station 202 may be immediately processed without the mobile terminal 204 having to recoyer from a dormant state. When in the first dormancy state, the mobile terminal 204 may go dormant for a short period of time (e.g., .64 seconds), and then check for new data on the channel. During the second dormancy state, the mobile terminal 204 may go dormant for an extended period of time (e.g., 1.28 seconds) aild then check for new data on the channel. A longer dormancy period may introduce additional latency in processing of the received data, because there may be a longer period of time before the terminal "wakes up" to process the data. However, the fact that the terminal performs fewer transmission and reception operations due to the longer latency period reduces battery consumption. The use of a dormancy signal allows for the mobile terminal to transition directly from a continuous reception state to the second dormancy state, thus eliminating time spent at the less efficient first dormancy state in circumstances where the transmission and reception operations are completed. An example method for managing these dormancy states using a dormancy signal is described further below with respect to Figures 3 and 4.

Figure 3 is a block diagram of a mcssage flow 300 between a mobile terminal and a wireless station to manage dormancy of the mobile terminal in accordance with cmbodiments of thc prcscnt invcntion. According to cmbodiments of the invention, a wirelcss station, such as the wirelcss station 202, may communicatc with a mobile terminal, such as the mobile terminal 204. The mobile terminal 204 may indicate to the wireless station 202 that the mobile terminal 204 has completed data transmission, and the wireless station may send a dormancy signal to the mobile terminal in response to receiving the end of data signal. The dormancy signal may allow the mobile terminal to transition directly to a dormant state from a continuous reception state without requiring expiration of one or more inactivity timers. At action 302, the mobile terminal 204 may receive system information from the wireless station 202.

Reception of the system information may include configuration data for the mobile terminal 204, such as the duration of dormancy for dormancy states, the duration of inactivity timers, whether the system is configured for processing dormancy signals, and the like. The system information may frirther include channel access parameters, scheduling information, or any other data to facilitate communications between the mobile terminal 204 and the wireless station 202.

At action 304, the mobile terminal 204 communicates with the wireless station 202. For example, the mobile terminal 204 may send and receive application data, voice data, channel status data, or any other data as may be transmitted between nodes of a network.

At action 306, the mobile terminal 204 indicates an end to data transmission operations. For example, the mobile terminal 204 may have no more user data to transmit to the wireless station 202. In this context, the end of data transmission may refer to a state in which the mobile terminal 204 has no messages intended for the wireless station 202 in an outgoing message queue, that an application communicating to the wireless station 202 has terminated, or any other state where the mobile terminal 204 has temporarily ceased communications with the wireless station 202, but will still be monitoring for data to be sent to or received from the wireless station (e.g., the communications channel may still be open, but the mobile terminal does not have a need to access the channel). The mobile terminal 204 may indicate an end of the data transfer operations to the wireless station 202 by modifkjing a flag (e.g., I bit) in a MAC: header, or by otherwise sending a signal to the wireless station 202 signi'ing an end to data transmission. For example, the mobile terminal 204 may indicate to the wireless station 202 via an uplink signal (e.g., as part of an uplink radio link control (RLC) protocol data unit (PDU) header, a MAC PDU header, a scheduling information message, a channel state information message, or a channel quality information message).

At action 308, the wireless station 202 may receive the end of data signal from the mobile terminal 204, and respond with a dormancy signal. As described above, the dormancy signal may be sent by the wireless station 202 to enable the mobile terminal 204 to bypass one or more inactivity timers and directly enter a dormant state. The dormancy signal may be sent via a downlink channel between the mobile terminal 204 and the wireless station 202. Sending of the dormancy signal in response to the end of data signal may allow the wireless station and the mobile terminal to perform a handshake operation, such that the wireless station 202 may acknowledge that the mobile terminal may enter a dormant state. Tn some embodiments, the mobile terminal 204 may immediately enter a dormant state after transmitting the end of data signal to the wireless station 202.

In some embodiments, the wireless station 202 may determine whether the mobile terminal 204 is equipped to process a dormancy signal. For example, during exchange of the system information at action 302, the wireless station 202 may determine whether the mobile terminal 204 can process the dormancy signal, and then send the dormancy signal only when the mobile terminal 204 is configured to properly process the dormancy signal. The dormancy signal may be sent after both the mobile terminal 204 has indicated an end to data transmission and the wireless station 202 has also determined that no more data is to be sent to the mobile terminal 204. The dormancy signal may be sent as a data transmission, as part of a channel scheduling transmission (e.g., as part of a Channel State Information (CSI) message or Sounding Reference Signal (SRS) message), as part of a message header (e.g., a flag set in a MAC header), or via any other signal transmitted from the wireless station 202 to the mobile terminal 204.

At action 310, the wireless station 202 receives and processes the dormancy signal. As described above, the dormancy signal may cause the mobile terminal 204 to transition directly from a continuous reception state to a dormant state. An example method for processing the dormancy signal is described further below with respect to Figure 4.

Figure 4 is a flow diagram depicting an example of a method 400 for processing a dormancy signal in accordance with embodiments of the present invention. The method 400 is operable to communicate with a wireless station, and to receive a dormancy signal at the end of communications with the wireless station.

The method 400 allows the mobile terminal to efficiently handle inactivity periods to conserve battery power while also minimizing device latency. The method 400 may be performed by a mobile terminal, such as the apparatus 100 described with respect to Figure 1 and/or the mobile terminal 204 described with respect to Figure 2. The method 400 may be performed by a processing means of the apparatus 100, such as the processor 102, a communications means, such as the communications interface 106, or some combination thereof At action 402, the method 400 may cause a mobile terminal to be in a continuous reception state. Tn the continuous reception state, the mobile terminal may actively monitor a channel for incoming data transmission, minimizing latency in processing of incoming data but also consuming more power than a dormant state.

The continuous reception state may be associated with active sending and receiving data from a wireless station. The mobile terminal may be caused to enter a continuous reception state via a processing means, such as the processor 102. Data may be received during the continuous reception state via a communications means, such as the communications means 106.

At action 404, the method 400 determines whether a dormancy signal has been received. As described above, the dormancy signal may cause the mobile terminal to transition directly to a dormant state. The mobile terminal may be configured with multiple dormant states, i.e. the mobile terminal may be capable of entering a plurality of different dormant states (in general, one dormant state at a time). These dormant states may be identified by the length of time that the mobile terminal may remain dormant before checking for new data. For example, dormant states may be referred to as "First Discontinuous Reception" (First DRX) and "Second Discontinuous Reception" (Second DRX). The terms "first" and "second" may define the length of time that the mobile terminal is dormant for each state, with earlier (e.g., the first) states having shorter dormancy timers than later (e.g., the second) states (e.g., .64 and 1.28 seconds, respectively). If a dormancy signal has been received by the mobile terminal, the mobile terminal may proceed directly to the Second DRX state at action 412, bypassing any inactivity timers and previous DRX states. Otherwise, the method 400 proceeds to action 406 to determine a status of an inactivity timer. The determination as to whether a dormancy signal has been received may be performed by a processing means, such as the processor 102.

In some embodiments, the dormancy signal may be generated by and received from the mobile terminal itself rather than from a wireless station. For example, a mobile terminal may generate a dormancy signal in response to sending an end of data signal. In this manner, the mobile terminal may unilaterally enter the dormant state without performing the handshake process (e.g., sending the end of data signal and receiving the dormancy signal in response).

At action 406, the method 400 determines whether more data is to be sent or received. This determination may be associated with a first inactivity timer. The first inactivity timer may control a first dormancy state for the mobile terminal. For example, every time data is received by or sent from the mobile terminal, the first inactivity timer may be reset. lfthe first inactivity timer expires, the mobile terminal may enter a first dormancy state, because expiration of the first inactivity timer may be indicative of an end to a data transmission operation. If more data is received, the first inactivity timer does not expire and the method returns to action 402 to process the additional data. If the first inactivity timer expires due to no new data being received, the method may proceed to action 408 to enter the First DRX state. The determination as to whether new data has been received may be performed by a processing means, such as the processor 102.

In some embodiments, inactivity timers may be eliminated in favor of dormancy states controlled directly by the wireless station 204 and/or mobile terminal 202. For example, the mobile terminal 202 may transition directly to a dormant state based on signaling between the mobile terminal and wireless station, without the inefficiencies caused by using inactivity timers.

At action 408, the method 400 causes the mobile terminal to enter the First DRX state. As described above, the First DRX state may cause the mobile terminal to go dormant for a period of time before checking for new data, thus conserving battery power. Because data transmissions may arrive in bursts, the First DRX timer represents a tradeoff in terms of battery power and latency. The power consumption may be lower than a continuous reception state, but the latency may be highcr.

However, the power consumption may be higher than a Second (e.g., longer dormancy timer) DRX state, but the latency may be lower than the Second DRX state.

The mobile terminal may be caused to enter the First DRX state by a processing means, such as the processor 102.

At action 410, the method 400 determines whether the mobile terminal needs to send or receive data. As described with respect to action 406, the determination as to whether the mobile terminal should return to the continuous reception state may be performed with the aid of an inactivity timer. As with action 406, when data is sent or received, the inactivity timer maybe reset. If new data is sent or rcceivcd, the mobile terminal may reenter the continuous reception state described with respect to action 402. If the inactivity timer expires, the mobile terminal may enter the Second DRX state at action 412. The determination as to whether new data is to be sent or rcccived, and/or whether the inactivity timer has expircd may bc performed by a processing means, such as the processor 102.

At action 412, the method 400 causes the mobile terminal to enter a Second DRX state if either a dormancy signal is received at action 404 or the second inactivity timer expires at action 410. Although the method 400 is described with respect to multiple dormancy states and the ability to reach a second dormancy state via one or more inactivity timers, the method 400 could also be implemented to allow the mobile terminal to only transition to a dormancy state in response to a dormancy sigilal.

Embodiments of the invention may also describe multiple dormancy states configured to wake up at different intervals, with different dormancy signals allowing for direct entry of different states. In some examples, different dormancy states may have different wakeup patterns. For example, a wireless station may indicate that a particular data transmission has a particular traffic pattern (e.g., periodic at a particular interval, a burst of data followed by a periodic transmission, a periodic transmission for a time followed by a burst transmission, or the like) and instruct the mobile terminal to enter a dormancy state corresponding to that traffic pattern.

Although the dormancy signal may typically instruct the mobile terminal to enter a longer dormancy state, the dormancy signal could instruct the mobile terminal to enter any dormancy state for which the mobile terminal may be configured (e.g., a shorter dormancy state rather than a longer dormancy state). Thc mobile terminal may be caused to enter the second dormaticy state by a processing means, such as the proccssor 102.

At action 414, thc mcthod 400 dctcrmines whcthcr new data has bcen received such that the mobile terminal should exit the dormancy state. As described above, this length of time between checks for data may be a function of the dormancy state, such that later dormancy states have less frequent wake up intervals, in order to conserve battery power at the expense of latency. The mobile terminal may be caused to check for sent or received data by a processing means, such as the processor 102.

It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware, firmware, processor, circuitry, and/or other devices associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory 104 of an apparatus employing an embodiment of the present invention and executed by a processor 102 of the apparatus. As will be appreciated, any such computer program instructions may be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus implements the functions specified in the flowchart blocks. These computer program instructions may also be stored in a computer-readable memory that may direct a computer or other programmable apparatus to thnction in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture the execution of which implements the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks.

Accordingly, blocks of the flowchart support combinations of means for performing the specified functions and combinations of operations for performing the specified functions for performing the specified functions. It will also be understood that one or more blocks of the flowchart, and combinations of blocks in the flowchart, can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

In some embodiments, certain ones of the operations above may be modified or further amplified. Furthermore, in some embodiments, additional optional operations may be included. Modifications, additions, or amplifications to the operations above may be performed in any order and in any combination.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other fratures 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 fixm the scope of the invention, which is defined in the accompanying claims.

Claims

Claims 1. A method of managing dormancy timers in wireless communications, the method comprising: determining that a mobile terminal has completed a data transfer operation; causing the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receiving a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy sial, causing, using a processor, the mobile terminal to enter at least one dormant state, wherein in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given pcriod of time elapses.
2. A method according to claim 1, wherein: the mobile terminal is capable of entering a plurality of different dormant states, the at least one dormant state is one of the plurality of different dormant states, and the dormancy signal instructs the mobile terminal to enter the at least one dormant state.
3. A method according to claim 2, wherein the dormancy signal comprises data indicating the at least one dormant state of the plurality of different dormant states.
4. A method according to any of claims 1 to 3, wherein the given period of time for the at least one dormant state is longer than one or more periods of time associated with the other of the plurality of different dormant states.
5. A method according to any of claims I to 4, wherein the mobile terminal is configured to enter the at least one dormant state in response to expiration of an inactivity timer, and wherein the dormancy signal causes the mobile terminal to enter at least one dormant state bypassing the inactivity timer.
6. A method according to any of claims I to 5, wherein the end of data signal is sent as part of at least one of an uplink radio link control protocol data unit header, an uplink medium access control protocol data unit header, a packet data convergence protocol protocol data unit header, a channcl state information message, a sounding reference signal, or a channel quality indicator message.
7. A method according to any of claims 1 to 6, further comprising negotiating channel access parameters for a wireless channel, whcrein the wireless channel access parameters include data indicating whether the mobile terminal is configured for receiving the dormancy signal.
8. A method according to any of claims I to 7, wherein the end of data signal is transmitted via an uplink channel and the dormancy signal is received via a downlink channel.
9. A method according to any of claims I to 8, wherein the dormancy signal is received as part of a nigh Speed Shared Control Channel (HS-SCCI-l) message, a Medium Access Control (MAC) header element, a Radio Link Control (RL.C) header element, or a MAC control element.
10. Apparatus for use in managing dormancy timers in wireless communications, the apparatus comprising a processing system adapted to cause the apparatus at least to: determine that a mobile terminal has completed a data transfer operation; cause the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receive a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy signal, enter at least one dormant state, wherein when the apparatus is in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given period of time elapses.
11. Apparatus according to claim 10, wherein: the apparatus is capable of entering a plurality of different dormant states, the at least one dormant state is one of the plurality of different dormant states, and the dormancy signal instructs the apparatus to enter the at least one dormant state.
12. Apparatus according to claim 11, wherein the dormancy signal comprises data indicating the at least one dormant state of the plurality of different dormant states.
13. Apparatus according to any of claims 10 to 12, wherein the given period of time for the at least one dormant state is longer than one or more periods of time associated with the other of the plurality of different dormant states.
14. Apparatus according to any ofclaims 10 to 13, wherein the processing system is further adapted to cause the apparatus to enter the at least one dormant state in response to expiration of an inactivity timer, and wherein the dormancy signal causes the apparatus to enter at least one dormant state bypassing the inactivity timer.
15. Apparatus according to any of claims 10 to 14, wherein the end of data signal is sent as part of at least one of an uplink radio link control protocol data unit header, an uplink medium access control protocol data unit header, a packet data convergence protocol protocol data unit header, a channel state information message a sounding reference signal, or a channel quality indicator message.
16. Apparatus according to any of claims 10 to 15, the processing system being further adapted to cause the apparatus to negotiate channel access parameters for a wireless channel, wherein the wireless channel access parameters include data indicating whether the mobile terminal is configured for rccciving the dormancy signal.
17. Apparatus according to any of claims 10 to 16, wherein the apparatus is capable of entering two different dormant states, the processing system being further adapted to cause the apparatus to: enter a first of the two different dormant states in response to expiration of a first inactivity timer; and enter a second of the two different dormant states in response to expiration of the first inactivity timer and expiration of a second inactivity timer.
18. A computer program adapted to perform a method of managing dormancy timers in wireless communications, the method comprising: determining that a mobile terminal has completed a data transfer operation; causing the mobile terminal to send an end of data signal in response to completion of the data transfer operation; receiving a dormancy signal in response to the end of data signal; and in response to receipt of the dormancy signal, causing the mobile terminal to enter at least one dormant state, wherein in the at least one dormant state, the mobile terminal disables reception of data for a given period of time and resumes data reception after the given period of time elapses.
19. The computer program of claim 18, wherein: the mobile terminal is capable of entering a plurality of different dormant states, the at least one dormant state is one of the plurality of different dormant states; and the dormancy signal instructs the mobile terminal to enter the at least one dormant state.
20. The computer program of claim 19, wherein the dormancy signal comprises data indicating the at least one dormant state of the plurality of different dormant states.