Patent Publication Number: US-2005143143-A1

Title: Device, system and method of universal-mode communication with power saving

Description:
BACKGROUND OF THE INVENTION  
      Universal Mobile Telecommunications System (UMTS) is a third generation (3G) of cellular mobile communications system that provides an enhanced range of multimedia services. The specifications defining UMTS are formulated by the 3rd Generation Partnership Project (3GPP), and may be found in “IMT-2000 DS-CDMA System”, Association of Radio Industries and Businesses (ARIB) Standard, ARIB STD-T63 Ver. 3.10, published Sep. 26, 2002. The UMTS communication system, as defined by 3GPP, may require compliance of Wideband Code Division Multiple Access (WCDMA), which is related to 3G standard, and Global System for Mobile Communications (GSM) or General Packet Radio Service (GPRS), which is related to 2.5 standard.  
      During an idle state, a wireless communication device is generally required to monitor a paging channel (e.g., a radio channel assigned to a base station and used to set up calls to mobile devices) in a cellular network in order to detect incoming calls. This procedure consumes current, and may impact strongly on the communication device power consumption. A communication device that supports UMTS (e.g., in universal or dual mode) generally operates in an idle state by performing cell reselection whenever the signal level from a base station serving the cell becomes weak, distorted, noisy, or hindered. Cell reselection may include selecting GSM served cells, WCDMA served cells, or any other wireless communication cell types. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Embodiments of the present invention may be better understood and appreciated from the following detailed description taken in conjunction with the appended drawings, it being understood that these drawings are given for illustrative purposes only and are not meant to be limiting, wherein:  
       FIG. 1  is a simplified block-diagram illustrating an exemplary communication system in accordance with some aspects of exemplary embodiments of the present invention; and  
       FIG. 2  is a flow chart illustrating an exemplary method of using a selected radio access technology, according to some aspects of exemplary embodiments of the present invention. 
    
    
      It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Additionally, like reference numerals may indicate corresponding, analogous, or similar elements.  
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
      In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention. However it will be understood by those of ordinary skill in the art that the embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the description of embodiments of the invention.  
      Some portions of the detailed description that follows are presented in terms of algorithms and symbolic representations of operations on data bits or binary digital signals within a computer memory. These algorithmic descriptions and representations may be the techniques used by those skilled in the data processing arts to convey the substance of their work to others skilled in the art.  
      An algorithm is here, and generally, considered to be a self-consistent sequence of acts, functions, or operations leading to a desired result. These may include physical manipulations of physical quantities. Usually, though not necessarily, these quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers or the like. It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.  
      Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing”, “defining”, “calculating”, “determining” or the like, refer to the actions and/or processes of a computer or computing system, or similar electronic computing devices, that manipulate and/or transform data represented as physical, such as electronic, quantities within the computing system&#39;s registers and/or memories into other data similarly represented as physical quantities within the computing system&#39;s memories, registers or other such information storage, transmission or display devices.  
      Embodiments of the present invention may include apparatuses or devices to perform the operations herein. Such devices, as described hereinbelow, may include various types of communication devices that may be used in conjunction with the present invention, including mobile stations, cellular telephones, laptop or notebook computers, Personal Digital Assistants (PDA&#39;s), mini computers, pocket computers, wearable computers, paging devices, servers, wire, wireless, or cable modems, or any other communication devices. Such communication devices may be universal mode devices, therefore operating using one or more Radio Access Technologies (RAT). For example, dual mode devices or multi-mode devices may be used, hereinafter referred to as “universal mode” devices, which are adapted to use multiple RATs.  
      Devices or apparatuses that may be used in conjunction with the present invention may be specially constructed for the desired purposes, or they may comprise a general-purpose computing devices selectively activated or reconfigured by a program stored in such a device. Such a program may be stored on a storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable to store electronic instructions, and capable of being coupled to a system bus for a computing device.  
      The processes and displays presented herein are not inherently related to any particular computing device or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.  
      Reference is now made to  FIG. 1 , which illustrates an exemplary communication system  100  in accordance with an aspect of an embodiment of the present invention. Communications system  100  may include, for example, two Base Stations (BS), e.g., Base Station  105  and Base Station  106 , which may transmit data to and receive data from base stations, cellular phones, paging services and other wireless transmission systems within at least one cell that may be served by respective BS  105  and  106 . BS  105  and  106  may communicate with a communication device  130  over a communication channel  120 . Communications system  100  may include any number of base stations. Communication channel  120  may be, for example, a wireless link of a wireless communications system, part of a wide-area-network (WAN), local-area-network (LAN) or any other network. For example, the system may be a Wireless Local Area Network (WLAN) system or a digital subscriber line (DSL) system, or other type of network. According to aspects of the invention, communication device  130  may be operated at a relatively low energy-consumption rate, by operating primarily or as much as possible using a selected RAT. A selected RAT may be defined as a RAT, for example, which consumes less energy (e.g., current) when the communication device operates in idle state, in comparison to when the communication device operates using an alternative RAT. Primary functioning in the selected RAT may be defined as active functioning in the selected RAT, wherever possible, for example, wherever an adequate signal is able to allow functioning of the communication device using the selected RAT. For example, a selected RAT of a UMTS universal mode communication device may be WCDMA, and therefore when such a communication device operates in idle state using WCDMA technology, less current is consumed in comparison to idle operation when using GSM technology. The various embodiments of the method described below may be performed by, for example, communication device  130  and/or an associated processing platform, for example, a processor and associated instructions as described in detail below, although other suitable devices and/or platforms may perform embodiments of the method.  
      Base stations  105  and  106 , which may be transmission and/or receiving stations in cellular communication system  100 . Base station  105  may have a transceiver  115  to generate signals for two or more communication devices  130  and/or other base stations using a particular RAT, e.g., GPRS. Base station  105 , for example, may be a serving base station, which may, for example, currently be serving communication data to and/or receiving communication data from communication device  130 . Base station  106 , for example, may be a neighboring base station, which may have a transceiver  116  to generate signals for two or more communication devices  130  and/or other base stations using a particular RAT, e.g., WCDMA. Base stations  105  and  106  may respectively include databases  110  and  111  to respectively store relevant system data for a cellular communications system. Base stations  105  and  106  may respectively include antennas  125  and  126 , such as, for example, internal antennas, dipole antennas, omni-directional antennas, monopole antennas, end fed antennas, circularly polarized antennas, micro-strip antennas, diversity antennas, and the like, to transmit signals to a plurality of communication devices  130  and/or base stations. A serving base station such as  105  or  106  may be a transmission station, for example, that is currently serving signals to and receiving signals from at least one cell or geographical area and may thereby be broadcasting signals to and receiving signals from one or more UMTS based communication devices  130 .  
      Communication device  130 , for example, a mobile station using UMTS technology, may include an antenna  155 , a transceiver  135 , which may include a transmitter, receiver, and any other suitable communication components. Transceiver  135  may enable receiving of incoming signals and transmitting of outgoing signals, via antenna  155 , if desired. Antenna  155  may be, for example, an internal antenna, dipole antenna, omni-directional antenna, monopole antenna, end fed antenna, circularly polarized antenna, micro-strip antenna, diversity antenna, and the like. Transceiver  135  may include, for example, a demodulator  140 . In some embodiments, transceiver  135  and antenna  155  may be implemented, for example, using separate and/or integrated units. Demodulator  140  may be used to demodulate received signals, and may be implemented in hardware and/or software.  
      Communication device  130  may include a processor  145 , which may include executable code that may enable operation of communication device  130  according to some embodiments of the present invention. Communication device  130  may include a memory unit  150 , to store relevant data and instructions etc. Communication device  130  may include a detector unit or mechanism  160 , located within one or more of the components of communication device  130 , based in hardware, software, or any combination thereof. Detector unit  160  may enable determination or identification of the RAT utilized by a serving base station  105  or  106 . Methods of RAT determination and identification are known to those skilled in the art of cellular communications.  
      Although the scope of embodiments of the present invention is not limited in this respect, processor  145  may include an application specific integrated circuit (ASIC), an application specific standard product (ASSP), a reduced instruction set circuit (RISC), a complex instruction set computer (CISC), a digital signal processor (DSP), a central processing unit (CPU), or any other suitable processor. System data, executable code, and/or instructions, etc., to enable computing unit  145  to perform methods of embodiments of the present invention, may be stored in a memory, disk, or other suitable storage device. Such instructions may be stored, for example, in memory  150 , such as a flash card, or other suitable storage medium. Instructions may include computer-readable code, algorithms, definitions, and calculations, etc. Any other suitable computing or communication components may be used. Execution of the instructions may be performed by processor  145 , or any other suitable components. The instructions may also be embodied in hardware or any suitable combination of software and/or hardware in accordance with specific implementations of embodiments of the invention.  
      Design considerations, such as, but not limited to, processor performance, cost and power consumption, may result in a particular processor design, and it should be understood that the design of processor  145  is merely an example, and that embodiments of the invention are applicable to other processor designs as well.  
      Although the scope of embodiments of the present invention is not limited in this respect, communication system  100  shown in  FIG. 1  may be part of a cellular communication system, with base stations  105  and  106  being transmission stations, and communication device  130  being a mobile station, a pager communication device, a personal digital assistant (PDA) and/or any other suitable communications device. In the case of a cellular wireless communication system, according to some embodiments of the present invention, communication system  100  shown in  FIG. 1  may be a 3rd Generation Partnership Project (3GPP), such as, for example, Frequency Domain Duplexing (FDD), Wideband Code Division Multiple Access (WCDMA) cellular system and the like.  
      Reference is now made to  FIG. 2 , which illustrates an exemplary method of power saving in a mobile station, for example, a UMTS universal mode communication device according to some exemplary embodiments of the present invention. In block  200 , communication device  130  periodically queries a serving base station, for example BS  105 , which may be serving the cell in which the communication device is located, to determine whether the serving base station  105  transmits signals using the communication device&#39;s selected predefined Radio Access Technology (RAT). In some embodiments for example, the RAT may be selected from GSM/GPRS or WCDMA etc. In other embodiments the RAT may be selected from PDC or WCDMA/CDMA etc. For example, a criterion for selecting may include selecting a RAT that enables relative power saving in the communication device during idle operation. For example, if communication device  130  is a dual mode communication device, supporting both WCDMA and GSM/GPRS RATs, communication device  130  may have a selected predefined RAT, such that monitoring a paging channel from, for example, base station  105  using the selected RAT, for example, GSM, may require lower energy consumption as compared to doing such monitoring using another RAT, for example, WCDMA. Such operation of communication device  130  using a selected predetermined RAT may enable operating in a power saving mode. Communication device  130  may initiate such a query periodically and/or randomly and/or any other desired method.  
      In block  205 , if the serving base station  105  transmits signals using the selected RAT, the power saving mode may be exited, and communication device  130  may continue normal operation using the communication device&#39;s selected RAT.  
      In block  210 , if the serving base station  105  does not transmit signals using the selected RAT, communication device  130  may initiate reading of system information from the serving base station  105 . Such system information may include data relating to the RAT&#39;s of neighboring base stations, for example, BS  106 . Neighboring base station  106  may be any base station that is able to provide signals to communication device  130 . Such reading of system information may be initiated irrespective of the signal strength being broadcast by the serving base station  105 . For example, an operation to read system information may be initiated when the signal being received by communication device  130  meets a predetermined criterion of adequacy or inadequacy, for example, when the signal is found to be sufficiently strong or weak in comparison to a predetermined value or using any other suitable value or criteria. For example, the determination of a GSM cell signal adequacy may be based on Received Signal Strength Indication (RSSI) measurements over a GSM Broadcast Control Channel (BCCH) carrier. An example of a determination of WCDMA cell signal adequacy may be based, for example, on a Received Signal Code Power (RSCP), a ratio of received pilot energy (Ec) to total received energy, or total power spectral density (Io) (Ec/Io) over a Common Pilot Channel (CPICH), or any combination known in the art. Other methods may be used for determining signal adequacy.  
      In block  215 , communication device  130  may determine whether there are one or more neighboring base stations that are transmitting adequate signals using the selected RAT. If there are no neighboring base stations transmitting adequate signals using the selected RAT, communication device  130  may exit the power saving mode, and return to the entry point before block  200 . An adequate signal may be defined as an incoming signal of sufficient strength to enable communication device  130  in an idle state to monitor a paging path from a base station of a cell.  
      In block  220 , if there is at least one neighboring base station  106  transmitting adequate signals using the selected RAT, communication device  130  may select a neighboring base station, e.g., BS  106 , to be its new serving base station where such adequate signals are transmitted using the selected RAT. In block  225 , the power saving mode may be exited.  
      Other functions, operations, or combinations of operations may be implemented.  
      While certain features of embodiments of the present invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present invention.