This invention relates to telecommunications, and more specifically, to an improved wireless communications device capable of interfacing to digital data networks and analog or digital wireless telephony networks such as CDMA, TDMA, GSM, and other types of such wireless telephony networks. The invention also relates to a technique of automatically roaming between the two types of networks and other communications networks as well. A networking system in which the inventive device may be utilized is also disclosed.
Wireless communication devices have become prevalent over the past several years, with most individuals utilizing one or more such devices such as cell phones, wireless e-mail devices, etc. Most such devices are capable of access over a wide geographic area that can often include either an entire continent, or even most of the world. Utilizing a cell phone as the illustrative example, the communications systems require that the phone be located and tracked on a variety of wireless telephony networks that are foreign to the cell phone's “home network”.
The home network is a network or small portion thereof associated with the carrier that provides the service to the cell phone, and is usually limited geographically or by other means. For purposes of explanation herein, we define a “roaming network” as a network covering an area where the cell phone or other device is located when it is not located on its home network. For example, if a cell phone is serviced by Verizon, it may be on its home network whenever it is within the portion of the Verizon network that is within the northeastern United States. However, when the cell phone is located in Mexico, and it must connect to the network via a Mexican cellular network, it is said to be roaming, or on a roaming network; i.e.; a network other than the basic northeastern United States coverage area. Additionally, if the cell phone is used in Seattle, it is also said to be roaming because it is not directly connected to the “home network”, the portion of the Verizon network covering the northeastern United States. Instead, it may be connected to a different portion of the Verizon network. The foregoing two types of roaming are termed on network roaming (e.g.; Seattle, where the user can connect to the Verizon network, but not to the portion that includes his normal coverage area) and off network roaming (e.g.; in Mexico). The present invention is applicable to both types of roaming, although we use off network roaming for exemplary purposes only herein.
Additionally, the user may be roaming even when he or she is physically within the purview of the home network. For example, the user may be connected via a roaming network because the home network is experiencing congestion or other problems, or because an alternative network is simultaneously available and is preferred for any of a variety of reasons. In the present specification, “roaming” is intended to cover any situation wherein the user is not directly connected to the home portion of the network, regardless of the reason why, and regardless of whether the cell phone is physically capable of connecting to that home network based upon its location.
Typically, an out of band signaling mechanism is used to allow communications with the cell phone when it is roaming. For example, the well-known SS7 out of band signaling protocol can be used by other networks to advise the home network that the cell phone is located within the service area of a roaming network. For example, consider a cell phone whose home network is a New York based wireless carrier. When the user of that cell phone travels to Mexico and uses the cell phone, the phone can still receive calls. This is accomplished because the cellular network in Mexico detects the presence of the cell phone and recognizes that the cell phone's home network is a New York based cellular network. The Mexican wireless cell network then uses out of band signaling, such as SS7, to advise switches in the New York based home network that the cell phone is presently located in Mexico. Calls that arrive for that cell phone at the home network are then forwarded via the public switched telephone network, to the Mexican cellular network, for completion to the subject cell phone.
Although the foregoing system is acceptable in most cases, it fails to utilize existing technology with respect to IP networks, such as wide area packet switching networks, including, but not limited to, the Internet, to maximize efficiency. More specifically, the foregoing prior art systems provide little or no mechanism for maximizing usage of packet switching in the Internet and other IP networks, and no technique of taking advantage of the resulting reduced costs and/or expanded coverage areas where there may be Internet access but no cellular coverage.
Presently, there exist Internet Protocol (IP) wireless devices, which communicate over packet switched data networks using a wireless mode. These devices may also roam to various other networks and service providers. However, unlike the case of cell phones, there is no technique for easily merging the widespread deployment of cellular networks typically utilized for telephones with the packet switching data networks utilized for wireless IP devices. Consequently, existing networks and systems fail to take advantage of the ability to merge the advantages of many different types of networks and devices.
Travelers with IP devices are also often able to log on to the Internet through wired connections to local area networks in homes and offices they are visiting, in hotel rooms, and in their own homes. Currently, they have no way to take advantage of these connections using their cellular voice phones.
In view of the foregoing, there exists a need in the art for combining the use of both wireless cellular networks previously intended for telephony applications and wireless IP networks previously intended for use with wireless IP devices but not specifically designed for voice service to give wider coverage for voice and other applications. There also exists a need to allow cell phones to connect though wired Internet connections.
The above and other problems of the prior art are overcome in accordance with the present invention. The inventive method and apparatus comprises a telephony device that can interface to an IP network. Instances of the device may connect to an IP network with a wireless protocol such as 802.11 or a wired connection such as Ethernet or both. The device can also interface to a typical cellular telephone network either on its own or through the attached cell phone. Depending upon location and configuration programmed by a user, the device may automatically select, or be configured to select, the appropriate network, whether an IP or cellular network. The device uses the connector built into most cell phones and may be manufactured in variations to fit each model of cell phone. The device may provide power to the cell phone.
In an enhanced embodiment, the device may automatically utilize either type of network, and may either automatically or manually be configured to utilize the addressing system employed by any of the networks. Means are provided within the network for converting addresses between those utilized by each of one or more networks. Accordingly, the cell phone attached to the device may indirectly through the agency of the device use any of one or more different addressing systems, and conversion among the addressing systems may occur in one or the other network if necessary.
A server 106 interfaces with an out-of-band signaling network such as 110 which uses SS7 or some other telephony signaling protocol and an IP network 105 as shown. The cellular network 112 is connected to various phones such as 111, and switching devices such as 107. An additional server 130 is also shown which is connected to IP network 105 and the PSTN 108.
Adapter 102 is a relatively small device into which a cell phone 101 can be inserted. The adapter 102 contains a network interface to communicate over a Local Area Network (LAN) 104. LAN 104 may itself be wireless, such as the WiFi type of network, or may represent any other type of LAN or other IP network. Adapter 102 serves to convert the typical cell phone protocol into the appropriate networking protocol utilized by network 104 and vice versa. It is also noted that while the adaptor 102 is shown as separate from the cell phone 101, it is also possible to build the adapter and cell phone as one unit, so that the cell phone is capable of operating in plural modes, one of which includes a direct connection to an IP network.
In operation of the exemplary embodiment of
The use of automatic selection of an appropriate interface can also prioritize various network interfaces in the event that plural such networks are available. For example, if a user is within range of a WiFi transceiver as well as a typical cell phone network transceiver, the user may set priorities as to which one would be selected first. Thus, the adapter 102 can be programmed to check first for WiFi, if it is available use it, and if not, check for an Ethernet, if not, check for a cell phone interface, etc. Additionally, rather than a fixed set of priorities being established, the user may establish rules and logic to allow the device to select the most efficient network. For example, signal strength, cost differences, whether the call is inbound or outbound, or other criteria may be accounted for in the network selection. In any event, adaptor 104 eventually determines that it is interfacing to an Ethernet, for example. After the appropriate network selection is made, communications are established between adaptor 102 and server 106 thru access point 103 and IP network 105
Adaptor 102 signals to cell phone 101 that a signal has been detected from a “tower” (actually Server 106 in the case where an IP network has been chosen) and cell phone 101 than transmits its identity to adaptor 102. Adaptor 102 translates the cell phone protocol identity sequence to IP packets and sends them to server 106. Server 106 recognizes that cell phone 101 is roaming from its home network from the identity information that has been sent.
Notably, the “roaming” may take place even when the cell phone and its user are physically located within the home coverage area of the cell phone user so long as the cell phone is also located within the coverage of a WiFi receiver or other IP access point, and the cell phone 101 has been configured to select the IP network with which to communicate, rather than the cellular telephony home network. This situation is also intended to be included in the definition of “roaming” because the cell phone is not obtaining network access through the usual portion of the cellular telephony network associated with the cell phone as its home network.
Continuing with the description of
Server 106 may then communicate to a switch and/or server 107 in the home network 112. After server 106 detects the relevant information from cell phone 101, it transmits messages through server/switch 107, informing server/switch 107 that cell phone 101 is presently communicatively coupled to IP network 105 rather than to its home network 112. This information can flow from server 106 to server 107 via a plurality of mechanisms. For example, SS7 signaling, an out of band signaling protocol typically used for call setup in conventional telephone networks, can be used. This information may also flow using any other out of band protocol, IP connections using public and/or private data connections such as the Internet, the PSTN, or any of a variety of other techniques. Further, this information may, but does not need to, include other information indicating that the network 105 is an IP network.
In one or more embodiments, the SS7 signaling is used between the IP network 105 and home network 112 may be identical to existing SS7 signaling, resulting in cellular networks being able to advantageously utilize the invention even if they only implement standard, prior art SS7 signaling. In other embodiments, more advanced signaling conveying other billing and identification/authentication information may be used. For example, 110 may represent an IP connection, over which server 106 transmits the appropriate authentication/identification information, billing information, etc. The communications line 110 is not intended to imply or be limited to any type of connection, and both the media and protocol utilized thereon may vary.
Regardless of the signaling used, switch/server 107 is eventually given a new phone number representing an entry point into IP network 105 servicing the cell phone 101. In the example of
In any case, after switch/server 107 is advised of the number at which to contact an IP network 105 presently servicing the cell phone 101, calls arriving from caller 111 to home network 112 destined for cell phone 101 would be rerouted through server 107 to server 130. As shown in the example of
It is noted that since either or both of switch/server 107 and servers 106 and 130 may be configured to communicate with various combinations of IP networks and telephone networks, plural techniques for routing the incoming call from home network 112 to IP network 105 may be utilized. Indeed, both the control and media associated with the call can be exchanged between the networks 112 and 105 using various combinations of in band and out of band signaling, IP and telephony signaling, and one or more intermediate gateways and switches
It is also noted that the addressing system utilized by cell phone 101 and implemented in the embodiment shown in
In operation, a call arriving from telephone 111 and directed to cell phone 101 is received in cellular network 112. Cellular network 112 forwards the call to server/switch 107 for forwarding to a sever designated by server 106 (e.g. 130) via links 113 and PSTN 108. The call is then completed via IP network 105, over the data network 104, through the access point 103, through adaptor 102, and ultimately to the cell phone 101. In the aforementioned process, server 106 provides the information to convert the dialed telephone number into an IP address on IP network 105. Such conversion is sufficient to route the call through IP network 105 to adaptor 102. Access point 103 is connected to network 104 and thus has the appropriate addressing information to complete the call to adaptor 102.
While the foregoing describes call flow in the case of an incoming call, the message and control flow for an outgoing call initiated by cell phone 101 is different. Referring still to
If the call is authorized, it may be completed through server 130 or some other server designated by server 106 to the PSTN 108 in the normal manner and billing information may be transmitted back to home network 112 by SS7 signaling or in any other convenient manner. In the special case where the called number is also presently within the called purview of server 106, or the purview of another IP network to which server 106 may connect, the call may be completed using IP all the way without ever utilizing the PSTN for the media and/or control stream
It is also noted that while the home network has been described as a cellular telephony network and the IP network is the roaming network, the invention is not so limited. An IP network may be utilized as the home network, and the cell phone 101 may be deemed roaming when it is on a cellular telephone network, or potentially other IP network. In this case, using present day protocols, the cellular network sends an ss7 message to the home IP network (which looks to it like another cellular network). The media server 130 associated with 106 owns the phone number of the called phone as far as the PSTN network is concerned. Whenever the server 130 receives a call (including cases above) it asks server 106 what to do with it. Server 106 will instruct it to forward the call via IP or PSTN as appropriate to the network onto which the user has roamed, which may be some other IP network, or the PSTN.
In operation, IP phone 201 may sometimes be located in an area covered by a conventional cellular network 210 and not connected directly to IP network 206. An adapter 202, which may also be built into the IP phone 201, is utilized to implement the connection between one of the cells 220 on cellular network 210, and the IP phone 201.
In operation, the IP phone may operate utilizing a conventional cellular telephone network in a manner that is the converse of that previously described with respect to cell phone 101. More specifically, when the adapter 202 converts IP phone 201 into a type of phone that may be utilized on cellular network 210, information identifying the cell phone 201 and its temporary phone number on cellular network 210 is transmitted from the cellular network 210 to a server 204 in the IP network 206 via communication line 214. The communication over line 214 may also be implemented as out of band signaling such as SS7, IP signaling, or any other type of signaling. Notably, by using SS7 or other standardized signaling, the wireless telephony network need not be altered from its present day operation.
Once a server 204 is notified that the IP phone 201 is actually roaming on a cell network 210, voice and data arriving for the IP phone at IP network 206 are rerouted to the cell network 210 for forwarding to the IP phone 201 over the cell network 210 through adapter 202.
As explained with reference to
When voice/data travels over the conventional cellular telephony networks, protocols for conventional cellular telephony are used, such as CDMA and other well-known protocols. When voice/data travel over packet switched data networks, the packet switching protocols such as TCP/IP and other well-known protocols are used. In the case of a single device that can act as a cell phone and IP data device or IP phone, the embodiments of
It is understood that the forgoing describes preferred embodiments of the invention, but that various modifications and additions will be apparent to those of skill in the art.
It is also possible that the same phone may act as a cellular phone to provide identifying information to the cellular network and to implement billing, but calls are actually routed to and from an IP network using an IP capability or adaptor with the phone. This, too, can be reversed so that the IP phone communicates billing and authentication information to the IP network, but calls may actually be placed over the cell network from a cell phone, which is potentially the same IP phone in a different mode.
The out of band signaling between the IP network and wireless cell network may also be used to convey data. Instant messaging, for example, utilizes SS7 signaling to convey meaningful data. When a user of cell phone 101 desires to send an instant message (“IM”), the IM is converted to IP by adapter 102 and transmitted to server 106. Server 106 converts the IM to SS7 signaling, and transmits the IM over an SS7 network to switch/server 107. Switch/server 107 may then forward the IM to the cell phone to which it is addressed, either directly or using other SS7 networks, or potentially unrelated networks. Switch/server 107, being related to the home cellular network of cell phone 101, may also be responsible for logging appropriate billing information so that the user gets properly billed for the transmission. It is also possible that the user to which the IM is directed is also within the purview of IP network 105, in which case the IM may go from server 106 directly to an access point or gateway on IP network 105, for forwarding to a destination user.
For an inbound IM utilizing SS7 messaging, assuming the source of the IM is not on IP network 105, such message arrives at server 106 via an SS7 network. The network originally directed the message to home cellular network 112, after which the IM was directed to server 106 based upon the techniques previously described herein. Upon arrival at server 106, the SS7 message may be converted to IP and forwarded to adapter 102 via IP network 105. Upon arrival at adapter 102, conversion from IP to cellular protocol is accomplished, and the message forwarded through to cell phone 101.
In other embodiments of the invention, any SS7 signaling may be sent via IP between the IP and wireless telephony networks, and out of band signaling may be used to convey a variety of different types of information that may be meaningful to a user, such as instant messaging.
It is also noted that the adapter could be a full PC, whereby call are routed to the address of the PC. Upon recognition by the PC that the incoming data is actually a telephone call, the PC may route the incoming call over a dedicated or other wireless or wired link to a phone, either a normal PSTN phone or a wireless phone. It is also possible to equip the adaptor with a normal PSTN interface, so it can translate between the cell phone protocol and the PSTN protocol. In still another variant of the adapter, the adapter may interface to the cellular network or the PSTN and also have the same functionality of a typical cordless phone, allowing RF communications between a handheld device and the adapter. In this case, the adapter functions as a base station and the handheld device may roam. Software within the adapter receives and transmits PSTN signals, from and to the PSTN, respectively, in accordance with normal telephone protocols, and translates such signals to cellular protocols. The cellular protocols are used to and from the wireless device, possibly over a wireless connection. The PSTN protocols may be used between the adapter and the PSTN, in the normal fashion utilized by a cordless phone base station of the present art. Thus, the adapter may interface between the cell phone and either an IP network, a cell network, a PSTN network or other network. Selection among any one or more such networks can be accomplished as described previously herein.
The foregoing is intended to describe only the preferred embodiments of the invention. Various other modifications and additions will be apparent to those of skill in the art, and are intended to be covered by the claims appended hereto.