Abstract:
In a wireless communication system including a campus infrastructure and a wide area infrastructure having a coverage overlapping the campus coverage, CDMA telephones/PDAs preferentially communicate with the campus infrastructure regardless of whether the devices achieve acquisition of the wide area system. The devices can know they are in the campus area based on geographic positioning information or based on probe messages that periodically are transmitted.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation of U.S. patent application Ser. No. 09/905,304, filed Jul. 13, 2001, pending, which application is incorporated herein by reference in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to wireless communication systems such as CDMA systems that provide tiered environments.  
         BACKGROUND OF THE INVENTION  
         [0003]    Wireless communication devices, such as but not limited to wireless telephones and personal digital assistants (PDAs) that communicate using Code Division Multiple Access (CDMA) spread spectrum modulation techniques, can be used to provide tiered communication services. For example, a CDMA telephone might be capable of receiving services from multiple overlapping CDMA systems, such as a primary, wide area CDMA system and a geographically smaller, so-called “campus” system. Establishing a campus system that serves a small region, e.g., a company&#39;s business complex, permits campus-specific features such as PBX to be made easily available to devices operating within the campus system. Moreover, using a campus system for communication between devices within the campus area advantageously off-loads communication traffic from the wide area system, thus enhancing network availability particularly for campus system users.  
           [0004]    A CDMA wireless device detects and acquires the system serving the area in which the device is located, based on received signal strength. As recognized herein, however, once a CDMA wireless device has acquired a system, it does not attempt to acquire an alternate system unless directed to do so by the serving system or unless the signal strength from the serving system becomes too weak. Thus, for instance, a CDMA wireless device might remain serviced by a wide area system even when it is present in a more preferred, local area that is served by a campus system.  
           [0005]    It is further the case that recent regulations mandate that wireless telephones have position sensing capability, either through triangulation techniques or onboard position systems such as GPS. Recognizing this and with the above critical observations in mind, the present invention provides the solutions disclosed herein.  
         SUMMARY OF THE INVENTION  
         [0006]    A wireless communication device is configured for communicating with a less preferred communication system, such as a wide area communication system and a more preferred communication system, such as a campus CDMA wireless system. The device includes a logic device for preferentially establishing communication with the more preferred communication system even when communication can be established with the less preferred communication system.  
           [0007]    In a preferred embodiment, the logic device preferentially establishes communication with the more preferred communication system based on the geographic position of the device. The position can be obtained from a GPS onboard the communication device or from a communication system using triangulation positioning techniques. Or, the device can periodically transmit a probe message to determine what communication systems are available to the device.  
           [0008]    In another aspect, a method for preferentially establishing wireless communication between a wireless communication device and a more preferred infrastructure in the presence of a communication path between the device and a less preferred infrastructure includes determining that communication is currently possible between the device and the more preferred infrastructure. The method also includes establishing communication between the device and the more preferred infrastructure regardless of whether a communication path between the device and the less preferred infrastructure exists.  
           [0009]    In still another aspect, a communication system includes a campus system and a wide area system having a coverage overlapping the campus system. Wireless communication devices are provided that are capable of communicating with both systems. The devices preferentially communicate with the campus system regardless of whether they achieve acquisition of the wide area system.  
           [0010]    The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a block diagram of a presently preferred wireless communication system;  
         [0012]    [0012]FIG. 2 is a flow chart of a first embodiment of the present logic;  
         [0013]    [0013]FIG. 3 is a flow chart of a second embodiment of the present logic; and  
         [0014]    [0014]FIG. 4 is a flow chart of a third embodiment of the present logic. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    Referring initially to FIG. 1, a wireless communication device, generally designated  10 , is shown that is configured for communicating with a wide area wireless communication infrastructure system  12  and a campus wireless communication infrastructure system  14 . In one presently preferred but non-limiting embodiment, the wireless device  10  is a code division multiple access (CDMA) telephone or data device such as a personal digital assistant (PDA), and the systems  12 ,  14  are CDMA systems. More specifically, the wide area system  12  includes base stations (BTS) and can include base station controllers (BSC) and other CDMA infrastructure components known in the art for serving a relatively large geographic area, whereas the campus system  12  can include base stations (BTS), base station controllers (BSC), and other CDMA infrastructure components known in the art for serving a relatively smaller geographic area that can be partially or completely overlapped by the wide area system  12 .  
         [0016]    In addition to CDMA, the present invention applies to devices  10  and systems  12 ,  14  that use other types of CDMA including but not limited to WCDMA, cdma2000, TD-SCDMA, as well as other wireless protocol such as but not limited to TDMA, UMTS, etc. In one non-limiting embodiment the communication device  10  is a mobile telephone made by Kyocera, Samsung, or other manufacturer that uses Code Division Multiple Access (CDMA) principles and CDMA over-the-air (OTA) communication air interface protocols such as defined in but not limited to IS-95A, IS-95B, UCDMA, IS-2000, and others to communicate with the systems  12 ,  14 . For instance, the wireless communication systems to which the present invention can apply, in amplification to those noted above, include Personal Communications Service (PCS) and cellular systems, such as Analog Advanced Mobile Phone System (AMPS) and the following digital systems: CDMA, Time Division Multiple Access (TDMA), and hybrid systems that use both TDMA and CDMA technologies. A CDMA cellular system is described in the Telecommunications Industry Association/Electronic Industries Association (TIA/EIA) Standard IS-95. Combined AMPS and CDMA systems are described in TIA/EIA Standard IS-98. Other communications systems are described in the International Mobile Telecommunications System 2000/Universal Mobile Telecommunications Systems (IMT-2000/UM), standards covering what are referred to as wideband CDMA (WCDMA), cdma2000 (such as cdma2000 1× or 3× standards, for example) or TD-SCDMA. The present invention applies to any wireless communication device  10 . In general, wireless communication devices to which the present invention applies may include but are not limited to a wireless handset or telephone, a cellular phone, a data transceiver, or a paging and position determination receiver, and can be hand-held, or portable as in vehicle-mounted (including cars, trucks, boats, planes, trains), as desired. However, while wireless communication devices are generally viewed as being mobile, it is to be understood that the present invention can be applied to “fixed” units in some implementations. Also, the present invention applies to data modules or modems used to transfer voice and/or data information including digitized video information, and may communicate with other devices using wired or wireless links. Further, commands might be used to cause modems or modules to work in a predetermined coordinated or associated manner to transfer information over multiple communication channels. Wireless communication devices are also sometimes referred to as user terminals, mobile stations, mobile units, subscriber units, mobile radios or radiotelephones, wireless units, or simply as “users” and “mobiles” in some communication systems.  
         [0017]    [0017]FIG. 1 shows that the wireless device  10  includes a housing  16  that holds a logic device  18  which functions in accordance with the disclosure below for preferentially establishing communication with the more preferred of the communication systems  12 ,  14  even when communication can be established with the less preferred of the communication systems  12 ,  14 . In an illustrative embodiment, the campus system  14  might be the more preferred system since it is desirable to provide devices  10  with particular services tailored to the campus system  14  when the devices  10  are within communication range of the system  14 . Also, when devices  10  communicate through the campus system  14 , the amount of communication traffic that the wide area system  12  must bear advantageously is reduced.  
         [0018]    It is to be understood that the present logic of the logic device  18  is executed in accordance with the flow charts discussed below. The flow charts herein illustrate the structure of the logic of the present invention as embodied in computer program software, logic circuits, or any other logic device. Those skilled in the art will appreciate that the flow charts illustrate the structures of logic elements, such as computer program code elements or electronic logic circuits, that function according to this invention. Manifestly, the invention is practiced in its essential embodiment by a machine component that renders the logic elements in a form that instructs a digital processing apparatus to perform a sequence of function steps corresponding to those shown.  
         [0019]    In other words, the logic may be embodied by a computer program that is executed by a processor within the device  10  as a series of computer-executable instructions. These instructions may reside, for example, in RAM of the device  10  or on a hard drive or optical drive of the device  10 , or the instructions may be stored on magnetic tape, electronic read-only memory, or other appropriate data storage device. In an illustrative embodiment of the invention, the computer-executable instructions may be lines of compiled C ++  compatible code. In one implementation, the logic is implemented in a mobile device using JAVA or BREW.  
         [0020]    The communication device  10  also includes a data storage device  20  within the housing  16 . Moreover, the communication device  10  can include a positioning device, such as but not limited to a global positioning system  22  supported within the housing  16 , to establish the geographic position of the communication device  10  for purposes to be shortly disclosed. Other positioning devices that can be used are disclosed in the following patent documents, all of which are incorporated herein by reference: U.S. Pat. Nos. 6,058,338 and 6,188,354, and U.S. patent application Ser. Nos. 09/741,631, 09/460,180, 09/430,618, and No. 60/239,318.  
         [0021]    Now referring to FIG. 2, one preferred implementation of the logic executed by using the logic device  18  can be seen. Commencing at block  24 , one or more “preferred” systems are defined.  
         [0022]    In the illustration above, the campus system  14  would be defined as a “preferred” system. This definition can be provisioned into the device  10  either during manufacture or subsequently, by a user manually inputting a preferred system identification or by downloading the definition using wireless communication channels and storing it in the storage device  20 . A third method could include downloading (or updating) such information using a BREW, JAVA, or other interface subsequent to manufacture at, e.g., a vendor facility. The definition of the preferred system or systems can include geographic boundaries of the system.  
         [0023]    Moving to block  26 , the geographic position of the communication device  10  is determined. This can be done using the output of the GPS  22 . Alternatively, it can be done using triangulation techniques, e.g., the signal from the communication device  10  as received at three or more base stations can be triangulated to determine the position of the communication device  10 , with the position being transmitted to the communication device  10  for storage thereof in the storage device  20 .  
         [0024]    Proceeding to decision diamond  28 , the logic device  18  can determine whether the communication device  10  is within the area of the preferred system, e.g., the campus system  14 . By “within the area” is meant located within the geographic communication boundary of the preferred system. If so, the logic proceeds to block  30  to establish communication with the preferred system by, e.g., acquiring a base station (BTS) within the infrastructure of the preferred system.  
         [0025]    On the other hand, if the communication device  10  is not within the geographic communication boundary of the preferred system, at block  32  the communication device  10  establishes communication with the less preferred system, e.g., the wide area system  12 , by, e.g., acquiring a base station (BTS) within the infrastructure of the less preferred system or other available system. It is to be understood that the logic of FIG. 2 can be executed at power-on and periodically thereafter, so that should the communication device  10  initially be forced to communicate with the less preferred system, it will periodically check its position to ascertain whether it is in the area of the more preferred system and if so, preferentially establish communication with the more preferred system regardless of whether it still receives a signal from the less preferred system. Once the communication device  10  acquires the more preferred system, block  34  indicates that it remains in communication with the more preferred system as long as a communication channel therewith exists, regardless of whether a stronger signal is received from an infrastructure component of the less preferred system. It is to be further understood that establishing communication with the less preferred system can also be a continuation of operation on the system, e.g., no change of status in terms of detecting the more preferred system.  
         [0026]    As an alternative to the position-based logic shown in FIG. 2, FIG. 3 shows that the communication device  10 , after one or more “preferred” systems are defined at block  36 , can periodically transmit a probe message at block  38  to determine whether it receives a response from the more preferred system, i.e., to determine whether the more preferred system is available to the communication device  10 . If it receives a response at decision diamond  40 , the more preferred system is acquired at block  42  in accordance with principles set forth above. Otherwise, the communication device  10  establishes communication with the less preferred but available system at block  44 . It is to be understood that establishing communication with the less preferred system can also be a continuation of operation on the system, e.g., no change of status in terms of detecting the more preferred system.  
         [0027]    Still further, FIG. 4 shows that after a preferred system is defined at block  46 , at block  48  the device can simply search periodically for a unique identifier that can be transmitted by the preferred system, e.g., an offset frequency. If the preferred system is not found at decision diamond  50 , a BTS in the less preferred system is acquired at block  52 . Otherwise, if desired to improve communication quality a decision can be made at diamond  54  whether the device is within a predetermined range of the preferred system and if so, a BTS in the preferred system is acquired at block  56 . Otherwise, the logic flows to block  52  to acquire the less preferred system.  
         [0028]    While the particular MOBILE COMMUNICATION DEVICE PREFERENTIAL SYSTEM SELECTION as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited as a “step” instead of an “act”.