gTfiTKMA DB SEBVTCtO IMALAMBRICT SHARED FOR IMOpiI-IMOq flTOP Tannic This invention relates to wireless / cellular and PCS telecommunications systems and more particularly to a wireless telecommunications switching system that provides shared service by a number of different user groups.
BACKGROUND OF THE INVENTION
Within the prior art, a shared service for tenants or tenants is provided by the telecommunications system of Lucent Technologies Definity. This service allows the owner of a building or shopping center to acquire a Definity telecommunications system and provide telephone services to the tenants of the building. Each tenant pays a fixed number of wired telephones and accesses a fixed number of trunk trunks. From the tenant's point of view, the telecommunications switching system seems to only serve that tenant. The advantage is that the tenant achieves access to a sophisticated telecommunications system that has a wide variety of features. Also, the total cost of obtaining telecommunications service for each tenant is lower. It has become common for large companies to install personal communications service systems (PCS * personal communication service) in fully REF: 25283 buildings controlled by the corporation. This allows employees to be constantly available through their PCS phones and has become widely used. However, in a building occupied by multiple tenants, it is not possible for each tenant to have their own PCS system simply because of the potential for interference between the systems and the added cost of having individual PCS systems. In addition, various tenants may want their PCS service to be through the building instead of just in the area rented by the tenant. An example of this situation is in an airport where each airline wants its employees to be in constant contact throughout the airport. Also, a tenant may wish to provide PCS service to the employees of all tenants. An example of such tenant would be a restaurant or bank located within the building who wishes to provide PCS access as a service to its customers. For these reasons, a wireless switching system that provides the shared tenant service in a multi-tenant building seems to be a desired or convenient solution. This method is undesirable since the cost of the base stations and the installation of these base stations represents a large cost factor of a wireless switching system. In addition, different tenants may well wish to have different levels of service. For example, a tenant might want their employees to only have wireless service within the portion of the building rented by the tenant; while other tenants may want their employees to have access to a base station throughout the building. Each tenant will be charged for each base station to which they have access. The U.S. Patent No. 5,530,945 describes a wireless shared tenant service. The solution of the U.S. Patent No. 5,530,945 is to allow a wireless terminal to register any base station; and then if that base station is not accessible to the wireless terminal, remove the wireless terminal from the base station. The problem with this solution is that a wireless phone that has an employee who was only authorized for limited use, constantly try to register it at the base stations where it could not register. This generates a large amount of administrative traffic for the wireless switching system and also reduces the availability of the base stations to authorize the wireless terminals. COHPEHDIQ DB LA IHYBiglflg This invention is aimed at solving this problem and other disadvantages of the prior art. According to the invention, each wireless terminal is limited with which base stations it tries to establish communication. Advantageously, in a first and second modalities, this is done by the wireless switching system or another system that has the ability to store within each individual wireless terminal, a list of base eßtacioneß that can be employed by that wireless terminal. When a wireless terminal is first registered in the wireless switching system, the wireless switching system will respond to the identification code of the wireless terminal to transmit a list of the base stations that can be used by the wireless terminal to the wireless terminal. The wireless terminal then stores that list for future use. In a third mode, each tenant will be assigned a group number, each of the base stations will periodically transmit the numbers of the groups that can access the base station. A wireless terminal checks these group numbers before attempting to register to a base station. Other and additional aspects of the present invention will be apparent during the course of the following description and by reference to the accompanying drawing. B -BVB DBSCRIPTITION OF THE DRAWING Figure 1 illustrates in the form of a block diagram, a wireless switching system to implement the inventive concept; Figure 2 illustrates in flow chart form, a first embodiment of the invention;
Figure 3 illustrates in flow chart form, a second embodiment of the invention; Figure 4 illustrates in flow chart form, a third embodiment of the invention; Figure 5 illustrates in flow chart form, a fourth embodiment of the invention; Figure 6 illustrates in flowchart form the manner in which a wireless terminal receives a tenant or a base station or tenant list from a computer;
Figure 7 illustrates in the form of a flowchart operations performed by a wireless switching system to implement the invention; and Figure 8 illustrates in block diagram form a wireless terminal. mraffiTPCTPií PBT? T-Mnft Figure 1 illustrates a wireless switching system having a plurality of base stations at 102 »
116 interconnected to the wireless switching system 101. Each of the base stations of the group of tenants is engaged in servicing the wireless terminal as designated by the tenant, such as the tenant 118. Tenants
117 to 123 occupy space within a common building such as an office building, shopping center or airport. While base stations are dedicated to serving wireless terminals designated by a particular tenant, base stations can physically disperse by covering areas outside the physical space rented by the tenant in the building. Also to illustrate one aspect of the invention, the tenant 121 makes its base stations 102-103 available to all wireless terminals authorized to connect to the wireless switching system 101. The result is that the wireless terminal 124 can be registered in the base stations 112. -113 and the base stations 102-103. Similarly, the wireless terminal 126 may register in the base stations 114 to 116 and the base stations 102 to 103. A person skilled in the art can easily see that there would be a large number of wireless terminals using the wireless switching system 101. Consider the following example of a first and second modalities. When the wireless terminal 124 searches for a base station in which it registers, it queries an internal list of base stations in which it is allowed to register. In the present example, the wireless terminal 124 can register in the base stations 112-113 and 102-103. Each base station transmits its identification as part of the information that the wireless terminal 124 interrogates when searching for a base station in which to register. The wireless terminal 124 ignores all base stations except those that are included in its internal list. In this way, the wireless terminal 124 is restricted to using the base stations 102-103 and 112-113. The list of base stations in the first mode is transmitted to the wireless terminal 124 by the wireless switching system 101, when the wireless terminal 124 registers in the wireless switching system 101 and requests the list. Also, if the list has changed since the wireless terminal was last registered, the wireless switching system 101 automatically transmits the list after registration. The wireless switching system 101 responds to the identification code of the wireless terminal 124 to examine an internal table to determine to the tenant which wireless terminal 124 is assigned. Once the tenant is determined, the wireless switching system 101 accesses the base stations that can be used by the tenant and downloads this information from the wireless terminal 124. Alternatively, in a second mode, the owner of the switching system wireless 101, provides a separate computer installation to which the wireless terminal 124 is initially connected and the base station list is downloaded to the wireless terminal 124. Consider the following examples of a third and fourth embodiments of the invention. In the third and fourth modalities, each tenant is assigned a tenant identification number. Each base station periodically transmits the tenant identification numbers for which the base station provides service. The tenant identification numbers identify the tenants in which the base stations can employ a wireless terminal. The tenant identification number may be stored in the wireless terminal by a separate computer installation or by downloading the tenant identification number to the wireless terminal, when the wireless terminal first registers in the wireless switching system 101. Before registering In a new base station, a wireless terminal interrogates the tenant identification number that is transmitted by the base station to determine whether a tenant identification number stored by the wireless terminal corresponds to the transmitted number. If there is no correspondence, the wireless terminal does not attempt to register at that base station. Figure 2 illustrates the first embodiment of the invention wherein the wireless terminal unit receives a list of base stations from the wireless switching system 101. When the wireless terminal 124 requires registration, it begins with the block 201. The decision block 202 determines whether the list of the base stations is present in the wireless terminal 124. If the answer in the decision block 202 is affirmative, then the control is transferred to the block 212. If the wireless terminal 124 was not previously registered in the system. 101 wireless switching, or has suffered a power failure, the list of base stations will not be presented inside the wireless terminal. If the answer is negative in decision block 202, block 203 is executed with what the wireless terminal 124 registers in any available base station. After registering at the base station, block 204 requests the list of base stations. Decision block 206 then determines whether the list of base stations has been received. If the answer is negative, error recovery is performed by block 207. If the answer is yes, decision block 206 stores the base station card and transfers control to decision block 205. The block of last decision determines whether the base station in which the wireless terminal 124 is currently registered, is in the list of base eßtacioneß. If the answer is yes, the control is transferred to block 223 since the record has already been made. If the answer is not in decision block 205, the control is transferred to block 213 which determines the base station whose signal is currently received at the highest level. The decision block 213 below determines whether the base station determined in block 212 is in the list of base stations. If the answer is yes, the control is transferred to the block 219 that registers the wireless terminal 124 in the wireless switching system 101.
After registration is completed, decision block 221 determines whether a new list of base stations has been received from wireless switching system 101. If a change has been made to the list of base stations for wireless terminal 124 since was last recorded in the wireless switching system 101, the wireless switching system 101 automatically transmits the new list of base stations to the wireless terminal 124. If the answer in the decision block 221 is affirmative, block 222 stores the new list of internal base stations to the wireless terminal 124 and the control is passed to the terminating block 223. If the response of the decision block 221 is negative, the control is transferred to the terminating block 223. Returning to the decision block 213, if the answer is negative, block 214 determines the base station that has the next strongest signal. Decision block 216 then determines whether this next base station is in the list of base stations. If the answer is affirmative, the control is transferred to block 219. If the answer is negative in decision block 216, decision block 217 determines whether a signal is received from any further base stations. If the answer is affirmative in decision block 217, the control is transferred back to 214. However, if there are no more base stations available for the wireless terminal 124 to register, block 218 indicates that made to the user of the wireless terminal 124 and the registration process ends. Figure 3 illustrates a second embodiment of the invention where the computer is used to load the base station list in the wireless terminal 124. Blocks 302 to 309 perform the same operations as blocks 212 to 219 in Figure 2. Without However, the functions performed by blocks 203 to 205, 221 and 222 are not required since the eßtacioneß baße list is not received from the wireless switching system 101. Figure 4 illustrates the third embodiment of the invention. In the third embodiment, the wireless terminal 224 stores a list of tenant ID numbers received from a computer. Each tenant illustrated in Figure 1, is assigned a tenant ID number. As previously described, if these tenants may wish to give all access to wireless terminals to their parking lot. Therefore, the wireless terminal 124 may have more than one tenant ID number in its stored tenant ID list. The tenant ID list is received offline from a computer. When the recording time begins, the execution begins at block 401. When block 402 determines the base station whose signal is the strongest. The decision blog 403 then decides whether the given base station transmits a tenant ID number that is in the tenant ID list for the wireless terminal 124. If the reply is affirmative in the 403 deci sion block, block 409 registers the wireless terminal 124 on the determined base station. If the response in decision block 403 is negative, block 404 determines the base station whose signal is the next strongest. The decision block 406 then decides whether the next base station transmits a tenant ID that is in the tenant ID list of the wireless terminal 124. If the answer in the 406 decryption block is affirmative, the control is transferred to the block 409. After executing this last block, the control is transferred to the terminating block 411. If the addition in the decision block 406 is negative, the decision block 407 determines whether a signal is received from another base station. If the decision in decision block 407 is affirmative, the control is transferred back to block 404. If the decision in decision block 407 is negative, block 408 indicates to the user that there is no base station available for registration and transfers control to the terminating block 411. Figure 5 illustrates the fourth embodiment of the invention in which the tenant ID list is received from the wireless switching system 101. When it is time for the wireless terminal 124 to register, the control is transferred from block 501 to decision block 502. Decision block 502 determines whether the list of tenant IDs is present in the wireless terminal. If the answer is affirmative, the control is transferred to block 512. If the answer is negative in decision block 502, block 503 is recorded in any available base statement. Block 504 then registers the tenant ID list from the wireless switching system 101. Decision block 506 determines when the tenant ID list is received. If the litter is not received, block 507 performs error recovery. When the tenant ID list is received and stored by the block 506, the control is transferred to the decision block 505. The decision block 505 determines whether the base station in which the wireless terminal 124 is currently registered transmits an ID of the same. tenant that is in the tenant ID list. If the response eß negative, the control ae transfers to block 512. If the answer is affirmative, the control is transferred to the terminating block 523 which terminates the registration since the wireless terminal 124 is already registered. Blocks 512 through 519 perform the same operations as blocks 402 or 409 of Figure 4 except that block 519 transfers control to decision block 521. Decision block 521 determines whether a new list of tenant IDs has been received from the wireless switching system 101. The latter switching system transmits a new list of tenant IDs if the list has changed for the wireless terminal 124 since its last registration. If a new list of tenant IDs is received, decision block 521 transfers control to block 522 that stores the list of tenant IDs. After executing block 522, control is transferred to terminating block 523. Figure 6 illustrates the flow diagram of wireless terminal 124 receiving information from a computer. The information can already be a list of tenants ID or a list of base stations. Block 601 determines when the wireless terminal 124 is connected to a computer. Decision block 602 then determines whether the wireless terminal is using the tenant ID. If the answer is negative, block 604 receives and stores the list of base stations. However, if the decision in decision block 612 is affirmative, block 603 receives and stores the list of tenant IDs. In any case, the execution ends in the terminating block 606. Figure 7 illustrates the operations performed by the wireless switching system 101 when implementing the first and fourth modes on a wireless terminal that is registered in a base station. In response to a registration request from a wireless terminal, the control is transferred from block 701 to decision block 702. The last decision block determines whether the wireless terminal is authorized to register in the currently used base station. if the answer is negative, the control ε transfers to the decision block 711 which determines whether the wireless terminal is requesting the tenant ID list. If the answer is affirmative, the control is transferred to block 712 that transmits the tenant ID list for that wireless terminal to the wireless terminal. After transmission of the tenant ID list, the control is transferred to block 76 which terminates the registration process and transfers control to block 709. Returning to decision block 711, if the answer is negative, decision block 713 determines whether the response wireless terminal is requesting the list of parking baße. If the response eß negative, the control is transferred to block 716. If the answer in decision block 713 is affirmative, block 714 transmits the list of base stations to the wireless terminal before transferring control to block 716. Returning to block of decision 702, if the wireless terminal is authorized to register in the base station, the control is transferred to the decision block 703 which determines if the wireless terminal has requested its list of tenant ID. If the answer is affirmative, the control is transferred to block 704 that transmits the tenant ID list to the wireless terminal. After executing in block 704, the control is transferred to decision block 708. The last decision block determines whether switching system 101 has an updated version of the list of base stations that has been updated since the last time it was received. recorded the wireless terminal 124. If the answer is yes, the block 717 transmits the new base station list to the wireless terminal and transfers control to block 718 that proceeds with the completion of registration in the block of terminations 709. If the answer is not in decision block 708, decision block 719 determines whether there has been an update to the list of tenant IDs. If the answer is affirmative, block 721 transmits the updated tenant ID list to the wireless terminal before transferring control to block 718. If the reply in decision block 719 is negative, the control is transferred to block 718. Returning to decision block 703, if the wireless terminal does not request the tenant ID list, the control is transferred to decision block 706. The last decision block determines whether the wireless terminal requests its list of base stations. If the answer is affirmative, the control is transferred to block 707 which transmits the list of base stations to the wireless terminal before transferring control to decision block 708. If the answer in decision block 706 is negative, control is transferred to the decision block 708. Figure 8 illustrates in block diagram form the internal circuits of the wireless terminal 106. The control unit 801 provides full control of the wireless terminal 106. The radio functions are performed by the elements 802, 803, 808, 809 and 806. The operation of these elements is described in greater detail in the Patent of the
E.U.A. No. 5,396,541 which is incorporated herein by reference. Telephone audio functions are performed by the elements
201, 810, 813, 814 and 212. The display 202 and the support circuits are represented by the display 816 in Figure 8. The element 805 represents the elements 203 to 211 of Figure 2 with support circuits. The control unit 801 uses the signal strength monitor 802 to perform the functions that have been described with respect to determining the signal strength of a baεe station. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following: