Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
  • H04W68/06—User notification, e.g. alerting and paging, for incoming communication, change of service or the like using multi-step notification by changing the notification area
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
  • H04W68/04—User notification, e.g. alerting and paging, for incoming communication, change of service or the like multi-step notification using statistical or historical mobility data
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W68/00—User notification, e.g. alerting and paging, for incoming communication, change of service or the like
  • H04W68/08—User notification, e.g. alerting and paging, for incoming communication, change of service or the like using multi-step notification by increasing the notification area

Definitions

• This invention relates to methods and systems for mobile communication, and more particularly to methods and systems for paging mobile stations.
• the goal of a mobile communication network is the interconnection of mobile stations with the Public Switched Telephone Network (PSTN) via a Mobile Switching Center (MSC) and a Radio Base Station (RBS).
• PSTN Public Switched Telephone Network
• MSC Mobile Switching Center
• RBS Radio Base Station
• a paging function is used to call a mobile station to find the station in the network.
• the page is broadcast upon a paging channel, which has a limited capacity. Thus, there is a need to limit the number of pages broadcast.
• a mobile station reports its location to the MSC by sending registration reports via the RBS.
• the mobile station is subsequently paged at the location at which it is registered.
• U.S. Patent No. 5,506,886 to Maine et al. discloses a paging system that allows a subscriber to call a destination controller and transfer subscriber identification and location information to the system. Thereafter, the system transmits a paging signal to the subscriber only at a location corresponding to the transferred location data.
• Conventional mobile registration is based on a single location concept, which is to say that whenever a mobile station moves from one local area to another, the registration in the old area is canceled, and a new registration is established in the new area.
• the MSC keeps track of only one location, the area in which the mobile station was most recently registered.
• a Location Area corresponds to a group of one or more cells in which a mobile station can move freely without updating its location.
• the Location Area registration is updated every time the mobile station enters a cell belonging to a new Location Area. The mobile station performs this updating by transmitting a registration report to the network when entering a new
• mobile stations may perform periodic location registration.
• Location Area In the interest of simplicity, the terms "Location Area” are used herein to describe both a Location Area and a Registration Location Area.
• a problem with such location registration is that a mobile station may move from one Location Area to another without renewing its registration.
• the mobile station cannot detect or acknowledge the page.
• the mobile station is temporarily not tuned to the paging channel upon which the page is broadcast, the mobile station is unable to detect the page. Therefore, the page has to be broadcast again, which presents a problem for a limited capacity paging channel.
• U.S. Patents No. 5,369,681 to Boudreau et al. and No. 5,533,094 to Sanmugan each disclose a paging system that broadcasts the paging signal only to locations or cells where a mobile station is most likely to be found or located.
• U.S. Patent No. 5,153,902 to Buhl et al. discloses a method in which previous mobile station registrations are used to determine where to page the mobile station.
• registration information is stored in a list in a home exchange when a mobile station registers. When the mobile station registers again, the new registration information is added to the list. Consequently, the list reveals the current registration of the mobile station as well as prior registrations made by the mobile station. The list is used by the home exchange to determine a suitable paging area.
• the paging areas typically employed are Location Areas, which can be quite large.
• the Registration Location Areas each contain up to sixty four cells.
• a smaller paging area would generally be sufficient and would be more efficient in using the limited paging channel resource. There is thus a need to reduce the size of the paging area in a mobile communication network while minimizing the number of mobile station registrations.
• a list of cell-identifying information is established representing the possible locations of the mobile station.
• the list is established by making contact between the mobile station and the mobile switching center, determining a cell in which the mobile station is located, and adding information identifying the cell in which the mobile station is located to the list.
• the mobile station is selectively paged within each cell identified by information in the list until a response is received.
• Figure 1 is a functional block diagram illustrating a mobile communication network according to an exemplary embodiment of the invention.
• Figure 2 illustrates a method for paging a mobile station according to an exemplary embodiment of the invention.
• FIG. 1 is a functional block diagram illustrating a communication network according to an exemplary embodiment of the invention.
• mobile station 230 is connected to a PSTN 260 via an MSC 250 and an RBS 240.
• the mobile station 230 travels between Location Areas LAI, LA2, LA3, LA4, each Location Area containing a plurality of cells 210.
• LAI Location Area
• LA2, LA3, LA4 Location Area containing a plurality of cells 210.
• the present invention is applicable to any number of mobile stations.
• each time the mobile station 230 makes contact with the RBS 240 and the MSC 250 information identifying the cell in which the mobile station is located is added to a Paging Hotlist that is maintained in the MSC 250.
• the mobile station 230 establishes contact with the RBS 240 and the MSC 250 through a connection on a Signalling Control Channel (SCCH), which may be a logical part of one of a set of predetermined control channels (CCHs) used by the network.
• SCCH Signalling Control Channel
• CCHs predetermined control channels
• each CCH corresponds to a respective cell, and this correspondence is established upon configuration of the mobile communication network.
• the MSC 250 detects a communication from the mobile station 230 on the CCH, and from the configuration information the MSC 250 "determines the cell in which the mobile station is located.
• information identifying the cell in which the mobile station is located is transferred to a subscriber database maintained in the network, and the cell-identifying information is also stored in the Paging Hotlist in the subscriber database.
• the subscriber database can be included in a Mobile Switching Subsystem (MSS) 252 of the MSC 250, and the Paging Hotlist can be stored in the Mobile Telephony Visiting (MTN) subscriber portion 256 of a Location Register (LR) 254 of the MSC.
• MTN Mobile Telephony Visiting
• LR Location Register
• the information in the Paging Hotlist is used for paging the mobile station 230 in a reduced area before paging the mobile station in a Location Area or performing a global page. In this way, the mobile station 230 is first paged in the cells where it is most likely to be found.
• the Paging Hotlist may be a list, for example, of the most recent five to ten cells in which a mobile station has originated a call, answered a page, or registered its location, or to which the mobile station has been handed over.
• the Paging Hotlist may also include a cell in which the last call was set up, if this cell is different from the cell in which the mobile station last originated a call.
• the Paging Hotlist list represents a range of possible locations of the mobile station that at any given time is significantly narrower than the usual Location Area.
• the Paging Hotlist would include identifying information for cells A, B, C, D, and E, rather than Location Areas LAI, LA2, and LA3.
• FIG. 2 illustrates a method for paging a mobile station according to an exemplary embodiment of the invention.
• the MSC 250 determines at step 100 whether an incoming call signal to a mobile station 230 has been detected. If an incoming call signal has been detected, the process proceeds to step 110 at which a paging operation begins.
• the MSC 250 issues pages within one or more of the cells identified by information listed in the Paging Hotlist.
• the MSC 250 can execute simultaneous, sequential, or a combination of both simultaneous and sequential paging in a plurality of different cells identified in the Paging Hotlist. For example, the MSC 250 may initially page the mobile station 230 in the cell in which the mobile station 230 is currently registered.
• the MSC 250 determines whether a page response has been received from the mobile station 230. If a response has been received, the process proceeds to step 130, at which the call is routed to the mobile station 230 in the cell from which the page response originated.
• step 120 If, at step 120, a page response has not been received from the initially paged cell(s), the process proceeds to step 140, at which a determination is made whether there are additional possible cell(s) identified by information stored in the Paging Hotlist. If there are such cells, the process proceeds to step 150 at which simultaneous paging in some or all of the remaining cells identified in the Paging Hotlist is executed. The process then returns to step 120 and a determination is made whether a page response signal has been received.
• the MSC 250 can optionally page the mobile station 230 within a Location Area at step 160. After completion of Location Area paging, a determination is made at step 170 whether a page response signal has been received. If a page response has been received, the process returns to step 130 and call routing is performed. If a page response signal has not been received, the process proceeds to step 180, at which an optional global page is performed. Then, the process proceeds to step 190, at which a determination is made whether a page response signal has been received. If a page response signal has been received, call routing is performed at step 130. If a page response signal has not been received, call rerouting is performed at step 200.
• a method and a system for paging a mobile station are provided by which the paging load imposed upon a mobile communication network is reduced without increasing the registration load.
• the paging area is reduced by using information identifying the cells in which the mobile station was located at the time the mobile station recently made contact with the communication network to determine the cells in which to page the mobile station. Since this information is already available in the network, using such information does not increase the registration load.

Landscapes

• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25375637

Family Applications (1)

Country Status (6)

Cited By (10)

Families Citing this family (1)

Citations (5)

• 1998
  • 1998-06-16 JP JP50429399A patent/JP2002505063A/ja active Pending
  • 1998-06-16 EP EP98930000A patent/EP0990363A1/en not_active Withdrawn
  • 1998-06-16 CN CN 98806177 patent/CN1260941A/zh active Pending
  • 1998-06-16 WO PCT/SE1998/001165 patent/WO1998059516A1/en not_active Application Discontinuation
  • 1998-06-16 AU AU79484/98A patent/AU7948498A/en not_active Abandoned
  • 1998-06-16 CA CA002294439A patent/CA2294439A1/en not_active Abandoned

Patent Citations (5)

Also Published As

Similar Documents

Legal Events