Method and apparatus for reducing power consumption during data transfer

An approach for reducing power consumption during data transfer is provided. A period of delayed release of one or more radio resources associated with a data flow is detected. In response to the detection, radio resource reduction information is generated for a data transfer during the period, wherein the radio resource reduction information specifies a reduced allocation of one or more radio resources. Control information is generated for transmission to a mobile station, wherein the control information specifies the radio resource reduction information.

BACKGROUND

Radio communication systems, such as a wireless data network (e.g., Global System for Mobile communications (GSM)/Enhanced Data Rates for GSM Evolution (EDGE) radio access network (GERAN)), provide users with the convenience of mobility along with a rich set of services and features. This convenience has spawned significant adoption by an ever growing number of consumers as an accepted mode of communication for business and personal uses. To promote greater adoption, the telecommunication industry, from manufacturers to service providers, has agreed at great expense and effort to develop standards for communication protocols that underlie the various services and features. One area of effort involves reducing the power consumption of the data transfers associated with many of the services and features. The functionalities demanded of wireless devices are often at odds with the design of the power system of the devices, in that generally more functions require more power consumption. Therefore, there is a need for more approaches for energy efficient use of radio resources.

SOME EXAMPLE EMBODIMENTS

According to certain exemplary embodiment, an approach provides for reducing power consumption during a data transfer by dynamically reducing the use of radio resources when there are gaps in the data stream of a data connection.

According to one embodiment, a method comprises detecting a period of delayed release of one or more radio resources associated with a data flow. The method also comprises generating, in response to the detection, radio resource reduction information for the data flow during the period, wherein the radio resource reduction information specifies a reduced allocation of the one or more radio resources. The method further comprises generating control information for transmission to a mobile station, wherein the control information specifies the radio resource reduction information.

According to another embodiment, an apparatus comprises at least one processor, and at least one memory including computer program code. The at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following: detect a period of delayed release of one or more radio resources associated with a data flow. The apparatus is also caused to generate, in response to the detection, radio resource reduction information for the data flow during the period, wherein the radio resource reduction information specifies a reduced allocation of the one or more radio resources. The apparatus is further caused to generate control information for transmission to a mobile station, wherein the control information specifies the radio resource reduction information.

According to another embodiment, a method comprises receiving a power saving command specifying radio resource reduction information that specifies a reduced allocation of one or more radio resources. The method also comprises monitoring one or more communication channels corresponding to the reduced allocation of the one or more radio resources for use in transfer of data during a period of delayed release of one or more radio resources associated with a data flow.

According to another embodiment, an apparatus comprises at least one processor, and at least one memory including computer program code. The at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following: receive a power saving command specifying radio resource reduction information that specifies a reduced allocation of one or more radio resources. The apparatus is also caused to monitor one or more communication channels corresponding to the reduced allocation of the one or more radio resources for use in transfer of data during a period of delayed release of one or more radio resources associated with a data flow.

According to another embodiment, an apparatus comprises means for detecting a period of delayed release of one or more radio resources associated with a data flow. The apparatus also comprises means for means for generating, in response to the detection, radio resource reduction information for the data flow during the period, wherein the radio resource reduction information specifies a reduced allocation of the one or more radio resources. The apparatus further comprises means for generating control information for transmission to a mobile station, wherein the control information specifies the radio resource reduction information.

According to yet another embodiment, an apparatus comprises means for receiving a power saving command specifying radio resource reduction information that specifies a reduced allocation of one or more radio resources. The apparatus also comprises means for monitoring one or more communication channels corresponding to the reduced allocation of the one or more radio resources for use in transfer of data during a period of delayed release of one or more radio resources associated with a data flow.

DESCRIPTION OF SOME EMBODIMENTS

Although the embodiments of the invention are discussed with respect to a wireless network compliant with the Third Generation Partnership Project (3GPP) Global System for Mobile communications (GSM)/Enhanced Data Rates for GSM Evolution (EDGE) radio access network (GERAN) architecture, it is recognized by one of ordinary skill in the art that the embodiments of the inventions have applicability to any type of communication system and equivalent functional capabilities.

FIG. 1is a diagram of a communication system capable of reducing power consumption during a data transfer, according to an exemplary embodiment. As shown inFIG. 1, a communication system100includes one or more mobile stations (MSs)101communicating with a base station103, which is part of an access network105(e.g., GERAN). The MSs101can be any type of mobile stations, such as handsets, terminals, stations, units, devices, multimedia tablets, Internet nodes, communicators, Personal Digital Assistants (PDAs) or any type of interface to the user (such as “wearable” circuitry, etc.). To achieve power savings, power saving logic107,109can be deployed within the mobile station101and base station103, respectively, according to certain embodiments. As will be more fully detailed below, such power saving logic107,109operate in conjunction with schedulers111,113to efficient transfer data, while minimizing use of system resources at the MS101(e.g., power can be reduced). Further, the MS101includes a transceiver (not shown) and an antenna system (not shown) that couples to the transceiver to receive or transmit signals from the base station103. The antenna system can include one or more antennas. As with the MS101, the base station103employs a transceiver, which transmits information to the MS101. Also, the base station103can employ one or more antennas for transmitting and receiving electromagnetic signals.

Typically, the base station103and MS101regularly exchange control information. Such control information, in an exemplary embodiment, is transported over a control channel on, for example, the downlink from the base station103to the MS101. By way of example, a number of communication channels are defined for use in the system ofFIG. 1. The channel types include: physical channels, and logical channels. For example, in GERAN, the packet data channel (PDCH) is a physical channel on which the logical channels such as the packet data traffic channel (PDTCH) and the packet associated control channel (PACCH) are mapped.

To ensure accurate delivery of information between the base station103and the MS101, the system ofFIG. 1utilizes error detection in exchanging information, e.g., Hybrid ARQ (HARQ). HARQ is a concatenation of Forward Error Correction (FEC) coding and an Automatic Repeat Request (ARQ) protocol. Automatic Repeat Request (ARQ) is an error recovery mechanism used on the link layer. As such, this error recovery scheme is used in conjunction with error detection schemes (e.g., CRC (cyclic redundancy check)), and is handled with the assistance of error detection modules and within the base station103and MS101, respectively. The HARQ mechanism permits the receiver (e.g., MS101) to indicate to the transmitter (e.g., base station103) that a packet or sub-packet has been received incorrectly, and thus, requests the transmitter to resend the particular packet(s).

In GERAN, a temporary block flow (TBF) is a logical connection between a MS101and a base station103that enables the unidirectional transfer of data and other signaling information over, for instance, a network cell. (See “Digital cellular telecommunications system (Phase 2+); General Packet Radio Service (GPRS); Mobile Station (MS)—Base Station System (BSS) interface; Radio Link Control/Medium Access Control (RLC/MAC) protocol,” 3GPP TS 44.060, ver. 8.3.0, Release 8, incorporated herein by reference in its entirety). A TBF used for the exchange of data in the direction from the base station103to the MS101is a downlink TBF. A TBF used for the exchange of data in the direction from the MS101to the base station103is an uplink TBF. The exchange of data between the MS101and the base station103in a given direction requires the exchange of control information between the MS101and the base station103in both directions. For example, a data transfer on a downlink TBF may require acknowledgement/negative acknowledgement (ACK/NACK) information in the uplink. Typically, a TBF is temporary and exists only for the duration of the data transfer (e.g., a TBF ends when all data blocks have been successfully transmitted).

Nevertheless, the release of radio resources associated with a data flow, such as the TBF, can be delayed on either the downlink (i.e., delayed release of downlink TBF mode) or the uplink (i.e., extended uplink TBF mode) beyond the duration of a data transfer if, for instance, additional data are expected to be transmitted within the near future, thus avoiding wasting time and radio resources to release and re-establish the TBF. For example, a delayed release of a downlink TBF may be used during a web browsing session when the corresponding web server is busy and cannot immediately respond. If the TBF were allowed to time out before the web server can provide the requested information, the web request would have to be reinitiated. Depending on the network load and other conditions, repeated timing out of data requests may result in degraded service to the end user. Therefore, it can be beneficial to maintain the TBF longer and avoid TBF release and establishment before a new request is transmitted to the network.

However, repeated or extended delays of a TBF release can greatly increase power consumption because both the MS101and the base station103continue to actively monitor the assigned radio resources (e.g., radio transmission timeslots) even when no data are being transmitted. It is noted that the problem of power consumption during a delayed release of the downlink TBF is worsened with the introduction of dual-carrier operation in which two simultaneous radio frequencies are used for a specific TBF. Under this scenario, the MS101and the base station103consume power monitoring the two frequencies at the same time.

To address this problem, the approach described herein reduces the radio resources used during a period of delayed release of the TBF (e.g., delayed downlink TBF release mode or extended uplink TBF mode) by, for example, reducing the number of transmission timeslots that are monitored. The approach also provides for fast resumption of normal operation (e.g., resumption of data transfer on all assigned timeslots) from the power saving mode (i.e., reduced radio resources mode). It is contemplated that the base station103or other network component decides the amount of radio resource reduction to use during the period of delayed TBF release (e.g., the reduction in the number of timeslots to monitor). Power saving logic107,109is included within the MS101and the base station103to implement the approach. It is also noted that, in exemplary embodiments, the reduction of radio resources is relative to the originally assigned resources and may be performed dynamically during the data gap. For example, the base station103originally assigns radio resources that include four transmission timeslots to the mobile station101. During a data gap, the base station103may reduce the resources to one timeslot. During the same data gap, the base station103may increase the resources to two timeslots. The increase to two timeslots nonetheless represents an overall reduction relative to the original allocation of four time slots.

FIG. 2is a flowchart of a process for reducing power consumption during a data transfer, according to an exemplary embodiment. In this example, it is assumed that the process involves a period of delayed release of one or more radio resources associated with a data flow (e.g., temporary block flow), whereby reduced resource allocation can be employed. As shown, in step201, the base station103determines information specifying a radio resource reduction (e.g., reduction in the number of timeslots to monitor). Next, the process generates a control information specifying the radio resource reduction information, and initiates transmission of the control information (e.g., power saving command) to the MS101, as in step203. The radio resource reduction information, for example, describes on which timeslot(s) the MS101should expect future occurrences of downlink data or an uplink resource allocation (e.g., an uplink state flag (USF)). In step205, the process initiates transmission of the power saving command to the mobile station101. The MS101then monitors only the specified channels until the MS101resumes normal operation—that is, use of the full radio resources (e.g., timeslots).

FIG. 3is a flowchart of a process for determining radio resource reduction information, according to an exemplary embodiment. As shown, the base station103determines, per step301, whether there is an active data transfer occurring over a TBF between the base station103and the MS101. The process determines whether there is an active data transfer, as in step303. If there is an active data transfer, the base station103and the MS101use all of radio resources (e.g., timeslots) assigned for the purpose (step305). If there is no active data transfer, the base determines an amount of reduced radio resources (e.g., timeslots) for use during the period of inactivity over the TBF, initiates the power saving mode (i.e., use fewer radio resources) at the base station103, and initiates signaling of the MS101to enter a corresponding power saving mode (steps307and309).

By way of example, the base station103signals to the MS101the radio resource reduction (e.g., timeslot reduction) information in the payload of a radio link control (RLC) data block for the downlink TBF. For instance, the radio reduction information is appended to the last logical link control (LLC) protocol data unit (PDU). In one embodiment, the radio resource reduction information is signaled as a bitmap (e.g., a “radio resource reduction bitmap”).

For the uplink TBF, the base station103may, for instance, deliver the radio resource reduction information in the content of a packet uplink acknowledgement/negative acknowledgement (PUAN) message. The radio resource reduction information corresponding to the uplink TBF indicates to the MS101the base station's intention to not transmit resource allocations (e.g., USF values) associated with the uplink TBF.

FIG. 4is a flowchart of a process for reducing power consumption during a data transfer using a mobile station101, according to an exemplary embodiment. Under this scenario, the MS101determines, as in step401, the receipt of a control information from the base station103specifying radio resource reduction information (e.g., timeslot reduction information). In step403, the MS101then initiates a power saving mode whereby it uses assigned radio resources (e.g., timeslots) according to the received control information containing the radio resource reduction information. In this manner, the MS101monitors one or more communication channels corresponding to the reduced allocation of the radio resources, per step405. The power saving mode is maintained until the MS101detects a data transfer (involving a new resource allocation) either on the downlink or the MS101begins transferring data on the uplink (steps407and409). Otherwise, the full radio resources are utilized, per step411.

More specifically, on the downlink TBF for example, the MS101receives an RLC data block including the control information containing the radio resource reduction information appended to the last LLC PDU conveyed by the RLC data block. Based on the radio resource reduction information, the MS101monitors for the occurrence of downlink data blocks addressed to the MS101only on the resource (e.g., timeslot) indicated in the radio resource reduction information. The MS101resumes normal operations (i.e., use all assigned radio resources such as timeslots) when the MS101receives a new RLC data block that does not contain the radio resource reduction information.

For the uplink TBF, the MS101receives the corresponding control information containing the radio resource reduction information in the PUAN message. The MS101applies the reduced radio resource configuration upon, for instance, the reception of the PUAN message. The MS101resumes use of all assigned radio resources (e.g., timeslots) when the MS101transmits new data on the assigned TBF. Correspondingly, the transmission of the new data by the MS101triggers the base station103to resume to normal operation and possibly more frequent scheduling of the assigned radio resources.

FIGS. 5A-5Care diagrams of radio link control (RLC) data blocks for signaling radio resource reduction information on a downlink TBF, according to various exemplary embodiments. As discussed previously, for the downlink TBF, the base station103signals reduced radio resource information to the base station103in the RLC data block appended after the last LLC PDU. Specifically, the radio resource reduction information (e.g., timeslot reduction information) is signaled as a bitmap (e.g., the “radio resource reduction bitmap”). The radio resource reduction bitmap is, for instance, either a 16-bit bitmap for a dual-carrier downlink or an 8-bit bitmap for a single-carrier downlink. In exemplary embodiments, the bitmap is a binary valued array representing the radio resource reduction information. Within the RLC data block, the presence of the radio resource reduction bitmap is indicated by a reserved length indicator value. The reserved length indicator values, for instance, are from 75 to 126.

FIG. 5Adepicts a single radio resource (e.g., timeslot) reduction bitmap501with filling octets. The filling octets are filler data inserted to complete the data block.FIG. 5Bdepicts a two radio resource (e.g., timeslot) reduction bitmap503with filling octets used for a dual carrier configuration. Each radio resource reduction bitmap corresponds to one of the carriers.FIG. 5Cdepicts a single radio resource (e.g., timeslot) reduction bitmap505with no filling octets.

By way of example, on receiving the RLC data block containing the radio resource reduction information, the MS101starts monitoring the indicated reduced radio resource (e.g., reduced number of timeslots) when the received state variable (V(Q)) is equal to the block sequence number (BSN) of the RLC data block containing the radio resource reduction bitmap, and no RLC data blocks with higher BSN were received (V(R)) (i.e., V(Q)=V(R)). It is contemplated that when operating in RLC acknowledged mode (defined in §9.1.6.2 of 3GPP TS 44.060, incorporated herein by reference), the MS101behavior is deterministic in the sense that the RLC data block is always received.

When operating in RLC non-persistent mode (NPM) (defined in §9.1.6.4 of 3GPP TS 44.060, incorporated herein by reference), the RLC data block may be discarded before it is correctly received by the MS101due to the expiration of the NPM transfer time. However, the network can nonetheless control the radio resource reduction by transmitting the radio resource reduction bitmap in an RLC data block containing a dummy LLC PDU. Delayed downlink TBF release operates specifically by sending downlink dummy LLC PDUs to prevent the release of the TBF. It is also contemplated that the base station103may use any modulation or coding scheme to ensure that the MS101receives the RLC data block containing the radio resource reduction information.

As described previously, the MS101resumes data reception using all assigned radio resources (e.g., timeslots) upon receiving an RLC data block with header including a BSN higher (modulo the entire sequence number space) than the BSN of the last RLC data block which triggered the power saving mode and the RLC data block itself does not contain the radio resource reduction information.

With respect to the uplink, the base station103may signal the MS101that the base station103intends to reduce the scheduling of uplink radio resources for a given TBF when the mobile station101has exhausted its supply of uplink data. For example, the reduced uplink radio resources include a reduced number of timeslots on which the base station103transmits resource allocations (e.g., USF). In exemplary embodiments, it is contemplated that the base station103reduces the frequency of resource allocations (e.g., USF) to a value that it is sufficient for the MS101to monitor, for instance, just one assigned resource (e.g., timeslot) for the allocation. On receipt of the allocation and subsequent data transmission, the MS101may resume normal operation.

The signaling of the radio resource reduction information for the uplink TBF is included in a PUAN message as a release extension as shown in Table 1. In exemplary embodiments, the radio resource reduction typically includes a reduction on at least one carrier. When operating in dual carrier mode, the base station103may also include radio resource reduction information for the second carrier as well. If the radio resource reduction on the second carrier is not included, then the MS101shall not monitor the second carrier for uplink resource allocations (e.g., USF) until the MS101resumes normal operation. It is noted that in multiple TBF scenarios, there may be other TBF allocated on the second carrier. In that case, the MS101continues to monitor the second carrier even after the power saving mode is activated for the first TBF if an allocation of other TBF(s) requires the MS101to do so. Additionally, although exemplary embodiments are described with respect to a single TBF mode of operation, it is contemplated that the power saving approach described herein also applies to a multiple TBF mode of operation. It is further contemplated that the base station103may use any other message coding scheme to transmit the radio resource reduction information to the MS101.

As previously discussed, the MS101applies the reduced radio resource configuration upon reception of the PUAN message containing the reduced radio resource information. The MS101then resumes data transfer using all assigned radio resources when the MS101transmits new data. Table 1, below, illustrates an exemplary PUAN message content.

The process for reducing power consumption during a data transfer can be performed over a variety of networks; an exemplary system is described with respect toFIGS. 6A-6D.

FIGS. 6A and 6Bare diagrams of different cellular mobile phone systems in which the mobile stations and the base station ofFIG. 1can operate, according to various exemplary embodiments.FIGS. 6A and 6Bshow exemplary cellular mobile phone systems each with both mobile station (e.g., handset) and base station having a transceiver installed (as part of a Digital Signal Processor (DSP)), hardware, software, an integrated circuit, and/or a semiconductor device in the base station and mobile station). By way of example, the radio network supports Second and Third Generation (2G and 3G) services as defined by the International Telecommunications Union (ITU) for International Mobile Telecommunications 2000 (IMT-2000). For the purposes of explanation, the carrier and channel selection capability of the radio network is explained with respect to a cdma2000 architecture. As the third-generation version of IS-95, cdma2000 is being standardized in the Third Generation Partnership Project 2 (3GPP2).

A radio network600includes mobile stations601(e.g., handsets, terminals, stations, units, devices, or any type of interface to the user (such as “wearable” circuitry, etc.)) in communication with a Base Station Subsystem (BSS)603. According to one embodiment of the invention, the radio network supports Third Generation (3G) services as defined by the International Telecommunications Union (ITU) for International Mobile Telecommunications 2000 (IMT-2000).

In this example, the BSS603includes a Base Transceiver Station (BTS)605and Base Station Controller (BSC)607. Although a single BTS is shown, it is recognized that multiple BTSs are typically connected to the BSC through, for example, point-to-point links. Each BSS603is linked to a Packet Data Serving Node (PDSN)609through a transmission control entity, or a Packet Control Function (PCF)611. Since the PDSN609serves as a gateway to external networks, e.g., the Internet613or other private consumer networks615, the PDSN609can include an Access, Authorization and Accounting system (AAA)617to securely determine the identity and privileges of a user and to track each user's activities. The network615comprises a Network Management System (NMS)631linked to one or more databases633that are accessed through a Home Agent (HA)635secured by a Home AAA637.

Although a single BSS603is shown, it is recognized that multiple BSSs603are typically connected to a Mobile Switching Center (MSC)619. The MSC619provides connectivity to a circuit-switched telephone network, such as the Public Switched Telephone Network (PSTN)621. Similarly, it is also recognized that the MSC619may be connected to other MSCs619on the same network600and/or to other radio networks. The MSC619is generally collocated with a Visitor Location Register (VLR)623database that holds temporary information about active subscribers to that MSC619. The data within the VLR623database is to a large extent a copy of the Home Location Register (HLR)625database, which stores detailed subscriber service subscription information. In some implementations, the HLR625and VLR623are the same physical database; however, the HLR625can be located at a remote location accessed through, for example, a Signaling System Number 7 (SS7) network. An Authentication Center (AuC)627containing subscriber-specific authentication data, such as a secret authentication key, is associated with the HLR625for authenticating users. Furthermore, the MSC619is connected to a Short Message Service Center (SMSC)629that stores and forwards short messages to and from the radio network600.

During typical operation of the cellular telephone system, BTSs605receive and demodulate sets of reverse-link signals from sets of mobile units601conducting telephone calls or other communications. Each reverse-link signal received by a given BTS605is processed within that station. The resulting data is forwarded to the BSC607. The BSC607provides call resource allocation and mobility management functionality including the orchestration of soft handoffs between BTSs605. The BSC607also routes the received data to the MSC619, which in turn provides additional routing and/or switching for interface with the PSTN621. The MSC619is also responsible for call setup, call termination, management of inter-MSC handover and supplementary services, and collecting, charging and accounting information. Similarly, the radio network600sends forward-link messages. The PSTN621interfaces with the MSC619. The MSC619additionally interfaces with the BSC607, which in turn communicates with the BTSs605, which modulate and transmit sets of forward-link signals to the sets of mobile units601.

As shown inFIG. 6B, the two key elements of the General Packet Radio Service (GPRS) infrastructure650are the Serving GPRS Supporting Node (SGSN)631and the Gateway GPRS Support Node (GGSN)633. In addition, the GPRS infrastructure includes a Packet Control Unit (PCU)635and a Charging Gateway Function (CGF)637linked to a Billing System639. Furthermore, in GPRS the Mobile Station (MS)641is composed of two parts—the mobile station601itself and the Subscriber Identity Module (SIM)643—which is a small card within the station601containing an integrated circuit.

The BSS665includes a BTS647, BSC645, and a PCU635. The PCU635is a logical network element responsible for GPRS-related functions such as air interface access control, packet scheduling on the air interface, and packet assembly and re-assembly. Generally the PCU635is physically integrated with the BSC645; however, it can be collocated with a BTS647or a SGSN631. The SGSN631provides equivalent functions as the MSC649including mobility management, security, and access control functions but in the packet-switched domain. Furthermore, the SGSN631has connectivity with the PCU635through, for example, a Frame Relay-based interface using the BSS GPRS protocol (BSSGP). Although only one SGSN is shown, it is recognized that that multiple SGSNs631can be employed and can divide the service area into corresponding routing areas (RAs). A SGSN/SGSN interface allows packet tunneling from old SGSNs to new SGSNs when an RA update takes place during an ongoing Personal Development Planning (PDP) context. While a given SGSN may serve multiple BSCs645, any given BSC645generally interfaces with one SGSN631. Also, the SGSN631is optionally connected with the HLR651through an SS7-based interface using GPRS enhanced Mobile Application Part (MAP) or with the MSC649through an SS7-based interface using Signaling Connection Control Part (SCCP). The SGSN/HLR interface allows the SGSN631to provide location updates to the HLR651and to retrieve GPRS-related subscription information within the SGSN service area. The SGSN/MSC interface enables coordination between circuit-switched services and packet data services such as paging a subscriber for a voice call. Finally, the SGSN631interfaces with a SMSC653to enable short messaging functionality over the network650. The MSC649is generally collocated with a Visitor Location Register (VLR)663database that holds temporary information about active subscribers to that MSC649. The data within the VLR663database is to a large extent a copy of the Home Location Register (HLR)651database, which stores detailed subscriber service subscription information. In some implementations, the HLR651and VLR663are the same physical database; however, the HLR651can be located at a remote location accessed through, for example, a SS7 network.

The GGSN633is the gateway to external packet data networks, such as the Internet613or other private customer networks655. The network655comprises a Network Management System (NMS)657linked to one or more databases659accessed through a PDSN661. The GGSN633assigns Internet Protocol (IP) addresses and can also authenticate users acting as a Remote Authentication Dial-In User Service host. Firewalls located at the GGSN633also perform a firewall function to restrict unauthorized traffic. Although only one GGSN633is shown, it is recognized that a given SGSN631may interface with one or more GGSNs633to allow user data to be tunneled between the two entities as well as to and from the network650. When external data networks initialize sessions over the GPRS network650, the GGSN633queries the HLR651for the SGSN631currently serving a MS641.

The BTS647and BSC645manage the radio interface, including controlling which Mobile Station (MS)641has access to the radio channel at what time. These elements essentially relay messages between the MS641and SGSN631. The SGSN631manages communications with an MS641, sending and receiving data and keeping track of its location. The SGSN631also registers the MS641, authenticates the MS641, and encrypts data sent to the MS641.

One of ordinary skill in the art would recognize that the processes for reducing power consumption during a data transfer may be implemented via software, hardware (e.g., general processor, Digital Signal Processing (DSP) chip, an Application Specific Integrated Circuit (ASIC), Field Programmable Gate Arrays (FPGAs), etc.), firmware, or a combination thereof. Such exemplary hardware for performing the described functions is detailed below.

A bus710includes one or more parallel conductors of information so that information is transferred quickly among devices coupled to the bus710. One or more processors702for processing information are coupled with the bus710.

A processor702performs a set of operations on information. The set of operations include bringing information in from the bus710and placing information on the bus710. The set of operations also typically include comparing two or more units of information, shifting positions of units of information, and combining two or more units of information, such as by addition or multiplication or logical operations like OR, exclusive OR (XOR), and AND. Each operation of the set of operations that can be performed by the processor is represented to the processor by information called instructions, such as an operation code of one or more digits. A sequence of operations to be executed by the processor702, such as a sequence of operation codes, constitute processor instructions, also called computer system instructions or, simply, computer instructions. Processors may be implemented as mechanical, electrical, magnetic, optical, chemical or quantum components, among others, alone or in combination.

Computer system700also includes a memory704coupled to bus710. The memory704, such as a random access memory (RAM) or other dynamic storage device, stores information including processor instructions. Dynamic memory allows information stored therein to be changed by the computer system700. RAM allows a unit of information stored at a location called a memory address to be stored and retrieved independently of information at neighboring addresses. The memory704is also used by the processor702to store temporary values during execution of processor instructions. The computer system700also includes a read only memory (ROM)706or other static storage device coupled to the bus710for storing static information, including instructions, that is not changed by the computer system700. Some memory is composed of volatile storage that loses the information stored thereon when power is lost. Also coupled to bus710is a non-volatile (persistent) storage device708, such as a magnetic disk, optical disk or flash card, for storing information, including instructions, that persists even when the computer system700is turned off or otherwise loses power.

Information, including instructions, is provided to the bus710for use by the processor from an external input device712, such as a keyboard containing alphanumeric keys operated by a human user, or a sensor. A sensor detects conditions in its vicinity and transforms those detections into physical expression compatible with the measurable phenomenon used to represent information in computer system700. Other external devices coupled to bus710, used primarily for interacting with humans, include a display device714, such as a cathode ray tube (CRT) or a liquid crystal display (LCD), or plasma screen or printer for presenting text or images, and a pointing device716, such as a mouse or a trackball or cursor direction keys, or motion sensor, for controlling a position of a small cursor image presented on the display714and issuing commands associated with graphical elements presented on the display714. In some embodiments, for example, in embodiments in which the computer system700performs all functions automatically without human input, one or more of external input device712, display device714and pointing device716is omitted.

Computer system700also includes one or more instances of a communications interface770coupled to bus710. Communication interface770provides a one-way or two-way communication coupling to a variety of external devices that operate with their own processors, such as printers, scanners and external disks. In general the coupling is with a network link778that is connected to a local network780to which a variety of external devices with their own processors are connected, e.g., a host computer782, an internet service provider784connected to the Internet790, and a server792. For example, communication interface770may be a parallel port or a serial port or a universal serial bus (USB) port on a personal computer. In some embodiments, communications interface770is an integrated services digital network (ISDN) card or a digital subscriber line (DSL) card or a telephone modem that provides an information communication connection to a corresponding type of telephone line. In some embodiments, a communication interface770is a cable modem that converts signals on bus710into signals for a communication connection over a coaxial cable or into optical signals for a communication connection over a fiber optic cable. As another example, communications interface770may be a local area network (LAN) card to provide a data communication connection to a compatible LAN, such as Ethernet. Wireless links may also be implemented. For wireless links, the communications interface770sends or receives or both sends and receives electrical, acoustic or electromagnetic signals, including infrared and optical signals, that carry information streams, such as digital data. For example, in wireless handheld devices, such as mobile telephones like cell phones, the communications interface770includes a radio band electromagnetic transmitter and receiver called a radio transceiver.

FIG. 8illustrates a chip set800upon which an embodiment of the invention may be implemented. Chip set800is programmed to carry out the inventive functions described herein and includes, for instance, the processor and memory components described with respect toFIG. 7incorporated in one or more physical packages. By way of example, a physical package includes an arrangement of one or more materials, components, and/or wires on a structural assembly (e.g., a baseboard) to provide one or more characteristics such as physical strength, conservation of size, and/or limitation of electrical interaction.

In one embodiment, the chip set800includes a communication mechanism such as a bus801for passing information among the components of the chip set800. A processor803has connectivity to the bus801to execute instructions and process information stored in, for example, a memory805. The processor803may include one or more processing cores with each core configured to perform independently. A multi-core processor enables multiprocessing within a single physical package. Examples of a multi-core processor include two, four, eight, or greater numbers of processing cores. Alternatively or in addition, the processor803may include one or more microprocessors configured in tandem via the bus801to enable independent execution of instructions, pipelining, and multithreading. The processor803may also be accompanied with one or more specialized components to perform certain processing functions and tasks such as one or more digital signal processors (DSP)807, or one or more application-specific integrated circuits (ASIC)809. A DSP807typically is configured to process real-world signals (e.g., sound) in real time independently of the processor803. Similarly, an ASIC809can be configured to performed specialized functions not easily performed by a general purposed processor. Other specialized components to aid in performing the inventive functions described herein include one or more field programmable gate arrays (FPGA) (not shown), one or more controllers (not shown), or one or more other special-purpose computer chips.

The processor803and accompanying components have connectivity to the memory805via the bus801. The memory805includes both dynamic memory (e.g., RAM, magnetic disk, writable optical disk, etc.) and static memory (e.g., ROM, CD-ROM, etc.) for storing executable instructions that when executed perform the inventive steps described herein. The memory805also stores the data associated with or generated by the execution of the inventive steps.

FIG. 9is a diagram of exemplary components of a mobile station (e.g., handset) capable of operating in the system ofFIG. 1, according to an exemplary embodiment. Generally, a radio receiver is often defined in terms of front-end and back-end characteristics. The front-end of the receiver encompasses all of the Radio Frequency (RF) circuitry whereas the back-end encompasses all of the base-band processing circuitry. Pertinent internal components of the telephone include a Main Control Unit (MCU)903, a Digital Signal Processor (DSP)905, and a receiver/transmitter unit including a microphone gain control unit and a speaker gain control unit. A main display unit907provides a display to the user in support of various applications and mobile station functions. An audio function circuitry909includes a microphone911and microphone amplifier that amplifies the speech signal output from the microphone911. The amplified speech signal output from the microphone911is fed to a coder/decoder (CODEC)913.

A radio section915amplifies power and converts frequency in order to communicate with a base station, which is included in a mobile communication system, via antenna917. The power amplifier (PA)919and the transmitter/modulation circuitry are operationally responsive to the MCU903, with an output from the PA919coupled to the duplexer921or circulator or antenna switch, as known in the art. The PA919also couples to a battery interface and power control unit920.

The encoded signals are then routed to an equalizer925for compensation of any frequency-dependent impairments that occur during transmission though the air such as phase and amplitude distortion. After equalizing the bit stream, the modulator927combines the signal with a RF signal generated in the RF interface929. The modulator927generates a sine wave by way of frequency or phase modulation. In order to prepare the signal for transmission, an up-converter931combines the sine wave output from the modulator927with another sine wave generated by a synthesizer933to achieve the desired frequency of transmission. The signal is then sent through a PA919to increase the signal to an appropriate power level. In practical systems, the PA919acts as a variable gain amplifier whose gain is controlled by the DSP905from information received from a network base station. The signal is then filtered within the duplexer921and optionally sent to an antenna coupler935to match impedances to provide maximum power transfer. Finally, the signal is transmitted via antenna917to a local base station. An automatic gain control (AGC) can be supplied to control the gain of the final stages of the receiver. The signals may be forwarded from there to a remote telephone which may be another cellular telephone, other mobile phone or a land-line connected to a Public Switched Telephone Network (PSTN), or other telephony networks.

Voice signals transmitted to the mobile station901are received via antenna917and immediately amplified by a low noise amplifier (LNA)937. A down-converter939lowers the carrier frequency while the demodulator941strips away the RF leaving only a digital bit stream. The signal then goes through the equalizer925and is processed by the DSP905. A Digital to Analog Converter (DAC)943converts the signal and the resulting output is transmitted to the user through the speaker945, all under control of a Main Control Unit (MCU)903—which can be implemented as a Central Processing Unit (CPU) (not shown).

The MCU903receives various signals including input signals from the keyboard947. The MCU903delivers a display command and a switch command to the display907and to the speech output switching controller, respectively. Further, the MCU903exchanges information with the DSP905and can access an optionally incorporated SIM card949and a memory951. In addition, the MCU903executes various control functions required of the station. The DSP905may, depending upon the implementation, perform any of a variety of conventional digital processing functions on the voice signals. Additionally, DSP905determines the background noise level of the local environment from the signals detected by microphone911and sets the gain of microphone911to a level selected to compensate for the natural tendency of the user of the mobile station901.

An optionally incorporated SIM card949carries, for instance, important information, such as the cellular phone number, the carrier supplying service, subscription details, and security information. The SIM card949serves primarily to identify the mobile station901on a radio network. The card949also contains a memory for storing a personal telephone number registry, text messages, and user specific mobile station settings.