WO2001043314A1

WO2001043314A1 - Two-way paging using satellite system subscriber units

Info

Publication number: WO2001043314A1
Application number: PCT/US2000/032343
Authority: WO
Inventors: Jim E. Helm; Peter J. Armbruster; David Philip Bush
Original assignee: Motorola, Inc.
Priority date: 1999-12-13
Filing date: 2000-11-27
Publication date: 2001-06-14
Also published as: AU1929101A

Abstract

A two-way paging system utilizes satellites to achieve a large effective paging service area coverage. A two-way pager (108) is coupled to a subscriber unit (106) in a satellite communications system. The satellite communications system includes at least one satellite (102), and at least one gateway (120). The gateway (120) communicates with a two-way paging infrastructure (132) and relays two-way paging information to and from the two-way pager (108). An effective paging service area is created that is limited only by the coverage of the satellite communications system. In some embodiments, the effective paging service area encompasses the entire globe.

Description

TWO-WAY PAGING USING SATELLITE SYSTEM SUBSCRIBER UNITS

Field of the Invention

The present invention relates generally to satellite systems and, in particular, to two-way paging in satellite systems.

Background of the Invention

Two-way pagers are devices that can send and receive paging information. Two-way pagers are typically small devices that can attach to a person's belt or reside in a person's pocket. They also typically have an output device, such as a display, and an input device, such as a miniature keyboard. Two-way paging systems typically offer services to paging service subscribers within a geographically limited area, or "paging service area." Within their paging service area, two-way pagers typically communicate directly with fixed terrestrial sites such as antennas on hilltops, buildings, or towers. Fixed terrestrial sites are typically dispersed about the paging service area such that a paging service subscriber can send and receive paging information when the subscriber is physically located within the paging service area. When a paging service subscriber leaves the paging service area, however, the two-way pager is not able to communicate with the fixed terrestrial sites, and the subscriber loses service.

For example, a two-way paging service subscriber may use a two-way paging service that operates in one city. As the subscriber moves about within this city, the two-way pager operates as expected. If the subscriber leaves the city, the subscriber loses service and the two-way pager ceases to operate. The problem of geographically confined paging service areas is not limited to a city as in the previous example. For example, a subscriber may have two-way paging service all across a country, but he or she may lose service when travelling to a different country.

To help alleviate this problem, a paging service subscriber could carry multiple pagers, one for each different paging service area to be visited. This is not a desirable solution to the problem, however, because the subscriber has to carry, and be familiar with the operation of, multiple two-way pagers. It would be desirable for a subscriber to be able to utilize a single two-way pager in an area larger than a single paging service area served by fixed terrestrial sites.

Accordingly, a significant need exists for a method and apparatus for providing two-way paging services in large geographical areas. Summary of the Invention

In accordance with the preferred embodiments, the present invention provides, among other things, method of communicating pages between a first two-way pager located outside a paging service area and a second two-way pager located within the paging service area. The paging service area is serviced by a terrestrial paging infrastructure. The method uses a subscriber unit that communicates with a satellite of a satellite communication system. The method comprising the step of receiving a first page from the first two-way pager at the subscriber unit over a link between the first two-way pager and the subscriber unit. The first page is destined for the second two-way pager. The subscriber unit has a paging interface module located therein for performing a paging protocol for receiving and transmitting of pages with the first two- way pager over the link.

The method also comprises the step of transmitting the first page from the subscriber unit to the satellite for routing the first page through the satellite communication system to a gateway of the satellite communication system. The gateway identifies a location of the second two-way pager within the service area and routes the first page to the terrestrial paging infrastructure for transmission within the service area to the second two-way pager. In accordance with the preferred embodiment, the method also comprises the step of receiving a second page from the satellite at the subscriber unit. The second page is destined for the first two-way pager and originating from the second two-way pager. The second page was received at the gateway from the terrestrial paging infrastructure and routed through the satellite communication system to the satellite for transmission to the subscriber unit. The gateway identifies a location of the first two-way pager as the satellite communication system. The method also includes the step of transmitting the second page from the subscriber unit to the first two-way pager over the link using the paging protocol. The first and second two-way pagers communicate with the terrestrial paging infrastructure using the paging protocol. In accordance with the preferred embodiments, the present invention also provides, among other things, a subscriber unit for communicating pages between a first two-way pager located outside a paging service area and a second two-way pager located within the paging service area. The paging service area is serviced by a terrestrial paging infrastructure and the subscriber unit communicates, among other things, two-way voice with a satellite of a satellite communication system. The subscriber unit comprises a paging interface module for receiving a first page from the first two-way pager at the subscriber unit over a link between the first two-way pager and the subscriber unit. The first page is destined for the second two-way pager. The paging interface module performs a paging protocol for receiving and transmitting of pages with the first two-way pager over the link. The subscriber unit also comprises a satellite interface for transmitting the first page from the subscriber unit to the satellite. The first page is routed through the satellite communication system to a gateway of the satellite communication system. The gateway identifies a location of the second two-way pager within the service area and routes the first page to the terrestrial paging infrastructure for transmission within the service area to the second two-way pager.

In accordance with the preferred embodiments, the satellite interface receives a second page from the satellite. The second page is destined for the first two-way pager and originates from the second two-way pager. The second page was received at the gateway from the terrestrial paging infrastructure and is routed through the satellite communication system to the satellite for transmission to the subscriber unit. The gateway identifies a location of the first two-way pager as the satellite communication system. The paging interface module transmits the second page from the subscriber unit to the first two-way pager over the link using the paging protocol.

Brief Description of the Drawings

The invention is pointed out with particularity in the appended claims.

However, a more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the figures, wherein like reference numbers refer to similar items throughout the figures, and wherein: FIG. 1 shows a two-way paging system in accordance with a preferred embodiment of the present invention;

FIG. 2 shows a subscriber unit and a two-way pager in accordance with a preferred embodiment of the present invention;

FIG. 3 shows a gateway in accordance with a preferred embodiment of the present invention;

FIG. 4 is a flowchart of a method for operating a two-way pager in accordance with a preferred embodiment of the present invention; and

FIG. 5 is a flowchart of a method for operating a subscriber unit in accordance with a preferred embodiment of the present invention.

Detailed Description of the Drawings

In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.

The method and apparatus of the present invention provide a mechanism for a two-way pager to communicate with a paging service while inside a paging service area served by fixed terrestrial sites as well as outside the paging service area. When the two-way pager is inside the paging service area serviced by fixed terrestrial sites, the two-way pager communicates with the fixed terrestrial sites. When the two- way pager is outside the paging service area, the two-way pager communicates with a subscriber unit in a satellite communications system, which in turn communicates with the paging service. A subscriber can use the same two-way pager irrespective of location, thereby providing convenient two-way paging service over a wide geographic area.

Turning now to the drawings in which like reference characters indicate corresponding elements throughout the several views, attention is first directed to FIG. 1. FIG. 1 shows a two-way paging system in accordance with a preferred embodiment of the present invention. Two-way paging system 100 is shown in FIG. 1 servicing two pagers, pager 140 and pager 108. Pagers 140 and 108 are two-way pagers. They are capable of receiving paging information, and they are also capable of sending paging information. Pager 140 is shown within paging service area 136. Within paging service area 136, fixed terrestrial sites, such as fixed terrestrial site 138, communicate with pagers for the purpose of sending and receiving paging information.

When a page is sent to pager 140, the page originates in, or is received by, paging infrastructure 132, and it is sent to fixed terrestrial site 138. The page is transmitted from fixed terrestrial site 138 to pager 140 on link 142. Link 142 represents a two-way link. Pager 140 can send pages back to paging infrastructure 132 by transmitting the pages on link 142 to fixed terrestrial site 138. Fixed terrestrial site 138 then sends the pages back to paging infrastructure 132. As long as pager 140 is within paging service area 136, pager 140 can receive uninterrupted service. When pager 140 leaves paging service area 136, however, service is interrupted because pager 140 is outside the range of fixed terrestrial site 138.

Discussions herein of communications in one direction, (e.g. from one device to another) are not meant to be limited to that direction. For example, a discussion of a communication from paging infrastructure 132 to pager 140 applies equally in the direction from pager 140 to paging infrastructure 132.

Pager 108 is outside paging service area 136. Pager 108 can be any type of two-way pager, including the same kind as pager 140 or a different kind. Two-way paging system 100 can send and receive pages to and from pager 108 even though pager 108 is outside paging service area 136. When paging infrastructure 132 has a page for pager 108, paging infrastructure 132 sends the paging information to a gateway in a satellite communications system, such as gateway 120. Paging infrastructure 132 can send paging information to gateway 120 in many different ways. For example, paging infrastructure 132 can send paging information to gateway 120 through Internet 130 or public switched telephone network (PSTN) 128. Paging infrastructure 132 can also have a dedicated line, such as a T1 line, to gateway 120. Also for example, paging infrastructure 132 can transmit paging information from antenna 134 to gateway 120 on link 124. In a preferred embodiment, link 124 is a radio frequency (RF) link that utilizes a well known RF paging protocol, such as the Reflex protocol. However, the invention is not limited to any particular type of paging protocol.

Gateway 120 transmits paging information to a satellite using antenna 122. The paging information can be sent to satellite 104 on link 118, or to satellite 102 on link 114. In some embodiments a single satellite, such as satellite 102, exists in the satellite communications system. In these embodiments, gateway 120 transmits the paging information to satellite 102 on link 114. The paging information is then retransmitted from satellite 102 to subscriber unit 106 on link 112. In other embodiments, multiple satellites, such as satellite 102 and satellite 104, exist in the satellite communications system. In these embodiments, gateway 120 can transmit paging information to satellite 102 as previously described, or gateway 120 can transmit paging information to satellite 104 on link 118. When paging information is transmitted to satellite 104, the paging information is retransmitted to satellite 102 on link 116, and it is then transmitted to subscriber unit 106 on link 112. Satellites 102 and 104 can be any type of satellite, including geosynchronous

(GEO), medium earth orbit (ME0), or low earth orbit (LEO). In a preferred embodiment, satellites 102 and 104 are part of a constellation of LEO satellites. LEO satellites move relative to the earth's surface, and as the number of satellites in the constellation increases, coverage of the earth also increases, and the "effective paging service area" also increases. The "effective paging service area" is the area within which pager 108 can be serviced. When the method and apparatus of the present invention are not employed, the effective paging service area is limited to paging service area 136. In contrast, the method and apparatus of the present invention provide a much larger effective paging service area. In some embodiments, links 112, 114, and 118 utilize time division multiple access (TDMA) signals. In these embodiments, signals on links 112, 114, and 118 are divided into time slots, within which multiple pagers can be assigned resources. In other embodiments, links 112, 114, and 118 utilize code division multiple access (CDMA) signals. In these embodiments, multiple pagers are assigned resources based on orthogonal pseudo-random codes. In other embodiments, links 112, 114, and 118 utilize frequency division multiple access (FDMA) signals. In these embodiments, multiple pagers utilize different frequency channels. In yet other embodiments, links 112, 114, and 118 utilize a combination of TDMA, CDMA, and FDMA signals. The invention is not limited to a particular type of multiple access scheme. Any suitable multiple access scheme can be utilized.

Satellite 102 communicates with subscriber unit 106 on link 112, and subscπber unit 106 communicates with pager 108 on link 110. Link 110 can be a radio frequency (RF) link, an optical (e.g. infrared (IR) or laser) link, a wireline link, or any other link capable of providing communications between subscriber unit 106 and pager 108. in a preferred embodiment, link 110 uses a paging protocol such as the Reflex protocol. However, the invention is not limited to any particular type of paging protocol.

Subscriber unit 106 provides multiple functions. Subscriber unit 106 provides voice and data services through the satellite communications system that includes satellites 102 and 104, and gateway 120. In addition to voice and data services, subscriber unit 106 provides two-way paging services through the satellite system when coupled to pager 108 via link 110. Link 110 is preferably the same type of link as link 142. When link 110 and link 142 are of the same type, pager 108 and pager 140 can, without modification, send and receive pages inside paging service area 136 and outside paging service area 136. For example, when pager 140 is inside paging service area 136, pager 140 communicates on link 142. When pager 140 is outside paging service area 136, it becomes like pager 108 and can communicate with subscriber units such as subscriber unit 106 on link 110. In a preferred embodiment, paging infrastructure 132 maintains a "location register" that lists the locations of known pagers within the system. For example, the location of pager 140 can be listed in the location register as fixed terrestrial site 138, and the location of pager 108 can be listed as the location of gateway 120. In this manner, pages destined for pager 140 are sent to fixed terrestrial site 138, and pages destined for pager 108 are sent to gateway 120. Also in a preferred embodiment, gateway 120 maintains, or has access to, a location register. The location register in gateway 120 preferably includes the location of subscriber units such as subscriber unit 106. The location register in gateway 120 also preferably includes the location of pagers coupled to subscriber units. For example, gateway 120 can maintain a location register that lists the location of pager 108 as being the same as subscriber unit 106.

Two-way paging system 100 is a duplex system within which pages can originate at any time from pagers within the system or from the paging infrastructure. For example, if a user of subscriber unit 106 and pager 108 originates a page, it can be sent without paging infrastructure 132 originating the communication. Likewise, pager 140 can also originate pages. In addition, a pager can originate any number of messages consecutively without waiting for a page to be received.

Two-way paging system 100 is advantageous in part because a paging subscriber who becomes familiar with the operation of a pager when inside a paging service area can continue to use the familiar pager when outside the paging service area. Two-way paging system 100 is also advantageous in part because when satellites 102 and 104 are part of a larger constellation of satellites, the "effective paging service area" grows. When the satellite constellation is large, pager 108 can potentially receive two-way paging services anywhere on the service of the earth. FIG. 2 shows a subscriber unit and a two-way pager in accordance with a preferred embodiment of the present invention. Two-way pager 208 includes user input/output interface 212 and paging system interface 216. User input/output interface 212 includes an output device such as an alphanumeric display, and it also includes an input device, such as a miniature keyboard. Paging system interface 216 communicates with user input/output interface 212 on node 214. Paging system interface 216 is configured to allow two-way pager 208 to communicate with subscriber unit 206 on link 210. Paging system interface 216 can be an interface dedicated to communicating with subscriber units, but in a preferred embodiment, paging system interface 216 is a single interface that can communicate with subscriber unit 206 and can also communicate with fixed terrestrial sites when pager 208 is within a paging service area.

Pager 208 can be a two-way pager, such as pager 108 (FIG. 1), coupled to a subscriber unit in a satellite communications system. Likewise, subscriber unit 206 can be a subscriber unit in a satellite communications system, such as subscriber unit 106 (FIG. 1). Subscriber unit 206 includes antenna 230, satellite interface 224, subscriber interface 222, and two-way pager interface 220. Antenna 230 communicates with satellites using link 232, and it also communicates with satellite interface 224. Satellite interface 224 sends signals to satellites using antenna 230, and it receives signals from satellites using antenna 230. When a page is received on satellite interface 224, it is sent to two-way pager interface 220 on node 228. Two-way pager interface 220 sends the page to pager 208 on link 210. Likewise, when two-way pager 208 has a page to be sent, pager 208 communicates with subscriber unit 206 on link 210. Two-way pager interface 220 can be a dedicated interface within subscriber unit 206, but in a preferred embodiment, two-way pager interface 220 is a removable pager communication module that can plug into subscriber unit 206. When two-way pager interface 220 is a removable module, subscriber unit 206 can be easily adapted to communicate with different types of pagers 208. For example, when two- way pager 208 uses a communications protocol that is standardized in one part of the world, two-way pager interface 220 can be adapted to use that protocol. If subscriber unit 206 is used in a part of the world having a different two-way paging protocol, subscriber unit 206 can be used with a two-way pager using that protocol by plugging in a two-way pager interface 220 designed to use that protocol.

Subscriber unit 206 also includes subscriber interface 222. When subscriber unit 206 is using voice or data services provided by the satellite communications system, satellite interface 224 communicates with subscriber interface 222 on node 226. Subscriber interface 222 can be an ear piece and microphone, a data connection, or any combination thereof.

The combination of subscriber unit 206 and two-way pager 208 is advantageous in part because subscriber unit 206 can provide voice and data services to a satellite communications system subscriber, and it can also provide two- way paging services to a two-way pager. A user of the two-way pager can continue to use the two-way pager even when outside a paging service area serviced by fixed terrestrial sites. For example, when two-way pager 208 utilizes a protocol standardized in the United States, and subscriber unit 206 is a subscriber unit capable of communicating anywhere in the world, a subscriber carrying both two-way pager 208 and subscriber unit 206 can have two-way paging services anywhere in the world.

FIG. 3 shows a gateway in accordance with a preferred embodiment of the present invention. Gateway 300 is a gateway in a satellite communications system, such as gateway 120 (FIG. 1). Gateway 300 communicates with satellites using antenna 320 and link 322. Link 322 can be any link capable of communicating with a satellite, such as link 114 or link 118 (FIG. 1). Antenna 320 is preferably a directional antenna capable of tracking satellites as they move relative to the surface of the earth. When antenna 320 is a directional antenna, gateway 300 can track satellites such as LEO satellites. The invention is not limited to implementation with LEO satellites, and it can also be implemented with geo-stationary (GEO) or mid-earth (MEO) satellites.

Satellite interface 302 communicates with two-way paging infrastructure interface 304 on node 306. Two-way paging infrastructure interface communicates with a two-way paging system using links 308, 310, and 312. In some embodiments, two-way paging infrastructure interface 304 communicates with a two-way paging system through a PSTN on link 310. In other embodiments, two-way paging infrastructure interface 304 communicates with a two-way paging system on RF link 308. In still other embodiments, two-way paging infrastructure interface 304 communicates with the two-way paging system via the Internet on link 312. Other types of links between gateway 300 and the two-way paging system, such as optical links, can be utilized without departing from the scope of the present invention.

When a page is received from a two-way paging system by gateway 300, it is sent to a satellite. For example, when two-way paging infrastructure interface 304 receives paging information on any of links 308, 310, or 312, the paging information is sent to satellite interface 302, which then transmits the paging information to a satellite on link 322. When gateway 300 receives paging information from a satellite on satellite interface 302, the paging information is sent to a two-way paging system by two-way paging infrastructure interface 304. Gateway 300 is advantageous in part because two-way paging information can be sent to a pager through a satellite communications system, thereby providing two-way paging services over a large geographical area. As a result, a user with a two-way pager can continue to use the two-way pager over this large geographical area. FIG. 4 is a flowchart of a method for operating a two-way pager in accordance with a preferred embodiment of the present invention. Method 400 begins in decision block 410 where it is determined whether the two-way pager is in a paging service area. The two-way pager can be a pager such as pager 108 or pager 140 (FIG. 1). If the two-way pager is in a paging service area, method 400 continues with block 440 where a first page is received from a fixed terrestrial site. The fixed terrestrial site can be a fixed terrestrial site on a hilltop, building, or tower, such as fixed terrestrial site 138 (FIG. 1). In block 450, a second page is sent by the two-way pager to the fixed terrestrial site.

Blocks 440 and 450 describe the operation of a two-way pager that is sending and receiving pages. It is not a requirement that a page be received prior to a page being sent. For example, a two-way pager operating with method 400 can send pages before receiving pages. In addition, a two-way pager operating with method 400 can send any number of pages prior to receiving a page or can receive any number of pages prior to sending a page. Blocks 440 and 450 correspond to the operation of the two-way pager when the two-way pager is within a paging service area, such as paging service area 136 (FIG. 1). When the two-way pager is within the paging service area, the two-way pager operates using the two-way paging infrastructure and fixed terrestrial sites.

When, in decision block 410, it is determined that the two-way pager is not in a paging service area, method 400 continues with block 420 where a first page is received from a subscriber unit, the subscπber unit being configured to communicate with a satellite system. The subscriber unit of block 420 can be a subscriber unit such as subscriber unit 106, and the two-way pager can be a pager such as pager 108 (FIG. 1). In block 430, a second page is sent from the two-way pager to the subscriber unit for transmission to the satellite system.

Blocks 420 and 430 describe the operation of a two-way pager that is sending and receiving pages. It is not a requirement that a page be received prior to a page being sent. For example, a two-way pager operating with method 400 can send pages before receiving pages. In addition, a two-way pager operating with method 400 can send any number of pages prior to receiving a page or can receive any number of pages prior to sending a page.

Blocks 420 and 430 correspond to the operation of a two-way pager when outside a paging service area, such as paging service area 136 (FIG. 1). By sending and receiving pages to and from a subscriber unit in a satellite system, an "effective paging service area" is created that is much larger than the actual paging service area serviced by fixed terrestrial sites.

Method 400 describes the operation of the two-way pager capable of communicating with fixed terrestrial sites and subscriber units in a satellite system, such as two-way pager 208 (FIG. 2). In the embodiment of FIG. 4, block 410 determines whether to communicate with a satellite system or a fixed terrestrial site by the location of the pager. In other embodiments, different conditions are used to make the determination. For example, in one embodiment, a user of the two-way pager can specify whether to use the fixed terrestrial site or the satellite system. In another embodiment, the determination is made by the paging service provider, and communicated to the pager. By operating a two-way pager using method 400, a user can advantageously utilize the same two-way pager within a paging service area, as well as outside the paging service area. FIG. 5 is a flowchart of a method for operating a subscriber unit in accordance with a preferred embodiment of the present invention. Method 500 begins in block 510, where a first page is received from a first satellite. In block 510, a subscriber unit, such as subscriber unit 106 (FIG. 1), receives a page that is addressed to a two- way pager. In block 520, the first page received in block 510 is transmitted to a two- way pager that is coupled to the subscriber unit through a link. The two-way pager can be a two-way pager such as pager 108 (FIG. 1). The link between the subscriber unit and the two-way pager can be an RF link, an optical link (e.g. an IR link), a wireline link, or the like.

In block 530, a second page is received by the subscriber unit from the two- way pager, and in block 540, the second page is transmitted to a second satellite. In some embodiments, the first satellite and the second satellite are the same satellite. Examples of these embodiments include a single GEO satellite, or a single LEO satellite. In other embodiments, the first satellite and the second satellite are not the same satellite, such as when the first and second satellites are satellites in a LEO constellation moving relative to the surface of the earth.

In block 550, a voice signal is received from a first satellite, and in block 560, the voice signal is provided to a subscriber. Blocks 550 and 560 describe the operation of the subscriber unit when providing voice services to a subscriber. Method 500 is equally applicable to subscriber units that provide data services to subscribers.

Method 500 describes the sending and receiving of pages, voice signals and data signals. These pages and signals can be sent and received in any quantity and in any order. For example, multiple pages can originate within a pager coupled to the subscriber unit prior to any pages being received. Also for example, multiple pages can be received by the pager prior to the pager originating any pages.

Method 500 is advantageous in part because the subscriber unit in a satellite system can provide voice and data services to a subscriber, while simultaneously providing two-way paging services to a pager that the subscriber is familiar with because of its use outside the satellite system.

In summary, the method and apparatus of the present invention provide a mechanism for utilizing two-way pagers over a large geographic area, potentially encompassing the entire globe. While we have shown and described specific embodiments of the present invention, further modifications and improvements will occur to those skilled in the art.

For example, while the method and apparatus of the present invention have been described with reference to mobile subscriber units, the method and apparatus of the present invention also apply to any type of equipment that is utilized in a satellite communications system. For example, in some embodiments of the present invention, the subscriber unit is a fixed unit providing voice and data services to multiple subscribers.

We desire it to be understood, therefore, that this invention is not limited to the particular forms shown, and we intend in the appended claims to cover all modifications that do not depart from the spirit and scope of this invention.

Claims

CLAIMSWhat is claimed is:

1. A method of communicating pages between a first two-way pager located outside a paging service area and a second two-way pager located within the paging service area, the paging service area being serviced by a terrestrial paging infrastructure, the method using a subscriber unit that communicates with a satellite of a satellite communication system, the method comprising the steps of: receiving a first page from the first two-way pager at the subscriber unit over a link between the first two-way pager and the subscriber unit, the first page being destined for the second two-way pager, the subscriber unit having a paging interface module located therein for performing a paging protocol for receiving and transmitting of pages with the first two-way pager over the link; and transmitting the first page from the subscriber unit to the satellite for routing the first page through the satellite communication system to a gateway of the satellite communication system, wherein the gateway identifies a location of the second two- way pager within the service area and routes the first page to the terrestrial paging infrastructure for transmission within the service area to the second two-way pager.

2. A method as claimed in claim 1 further comprising the steps of: receiving a second page from the satellite at the subscriber unit, the second page being destined for the first two-way pager and originating from the second two- way pager, the second page having been received at the gateway from the terrestrial paging infrastructure and routed through the satellite communication system to the satellite for transmission to the subscriber unit, the gateway having identified a location of the first two-way pager as the satellite communication system; and transmitting the second page from the subscriber unit to the first two-way pager over the link using the paging protocol wherein the first and second two-way pagers communicate with the terrestrial paging infrastructure using the paging protocol.

3. A subscriber unit for communicating pages between a first two-way pager located outside a paging service area and a second two-way pager located within the paging service area, the paging service area being serviced by a terrestrial paging infrastructure, the subscriber unit for communicating two-way voice with a satellite of a satellite communication system, the subscriber unit comprising: a paging interface module for receiving a first page from the first two-way pager at the subscriber unit over a link between the first two-way pager and the subscriber unit, the first page being destined for the second two-way pager, the paging interface module for performing a paging protocol for receiving and transmitting of pages with the first two-way pager over the link; and a satellite interface for transmitting the first page from the subscriber unit to the satellite, wherein the first page is routed through the satellite communication system to a gateway of the satellite communication system, the gateway identifying a location of the second two-way pager within the service area and routes the first page to the terrestrial paging infrastructure for transmission within the service area to the second two-way pager.

4. A subscriber unit as claimed in claim 3 wherein the satellite interface also for receiving a second page from the satellite, the second page being destined for the first two-way pager and originating from the second two-way pager, the second page having been received at the gateway from the terrestrial paging infrastructure and routed through the satellite communication system to the satellite for transmission to the subscriber unit, the gateway having identified a location of the first two-way pager as the satellite communication system, wherein the paging interface module transmits the second page from the subscriber unit to the first two-way pager over the link using the paging protocol.

5. A method of operating a two-way pager comprising: when the two-way pager is in a paging service area, transmitting a page from the two-way pager to a fixed terrestrial site; and when the two-way pager is located outside a paging service area, transmitting the page from the two-way pager to a subscriber unit configured to communicate with a satellite.

6. The method of claim 5 wherein the two-way pager is configured to communicate with the subscriber unit across a radio frequency (RF) link.

7. The method of claim 5 wherein transmitting the page from the two-way pager to the subscriber unit comprises transmitting the page to a subscriber unit configured to communicate with a plurality of satellites in low earth orbit.

8. A method of operating a subscriber unit in a satellite communications system comprising: receiving a first page from a first satellite; and transmitting the first page to a two-way pager.

9. The method of claim 8 further comprising: receiving a second page from the two-way pager; and transmitting the second page to the first satellite.

10. The method of claim 9 further comprising: receiving a voice signal from the first satellite; and providing the voice signal to the subscriber unit.

11. The method of claim 8 wherein the two-way pager is configured to communicate with the subscriber unit across a radio frequency (RF) link.

12. The method of claim 8 wherein the two-way pager is configured to communicate with the subscriber unit across an optical link.

13. A subscriber unit comprising: a satellite interface configured to communicate with a satellite; and a two-way pager interface configured to communicate with a two-way pager such that the subscriber unit relays paging information between the two-way pager and the satellite.

14. The subscriber unit of claim 13 further comprising a subscriber interface coupled to the satellite interface, the subscriber interface being configured to provide one or more satellite services to the subscriber unit.

15. The subscriber unit of claim 14 wherein the satellite services are voice services.

16. The subscriber unit of claim 14 wherein the satellite services are data services.

17. The subscriber unit of claim 13 wherein the two-way pager interface comprises a module slot configured to receive a module capable of communicating with the two-way pager.

18. The subscriber unit of claim 17 further comprising the module capable of communicating with the two-way pager.