The present disclosure relates generally to voice and data communications and, more particularly, to a wireless system and method for providing services to a wireless mobile terminal operating in a hybrid wireless network.
A wireless network may be composed of two sub-networks. The first subnetwork may be a Radio Access Network (RAN) which handles radio related issues, such as assigning radio resources to establish and maintain a communication session with a mobile communications device upon a request for service. The second sub-network may be a Core Network (CN) which links a user of a mobile device to a wireline network. The wireless network, its sub-networks, and mobile devices within the network may communicate using a standardized set of signals and commands known as a specification.
Available specifications for the wireless network may specify that the RAN and the CN of the wireless network are based on the same wireless technology. Such networks may be referred to as “homogenous networks.” For instance, if the RAN and the CN are based on a technology such as Global System for Mobile communications (GSM), a mobile subscriber using a GSM compliant device may utilize the network Likewise, if the RAN and the CN are based on a technology such as code division multiple access 2000 (CDMA2000), a mobile subscriber using a CDMA2000 compliant device may utilize the network.
However, due in part to incompatibilities between different specifications, such as GSM and CDMA2000, a mobile device may only be able to utilize networks based on a particular specification. This is a primary disadvantage of homogenous networks because, given the many wireless technologies that currently exist and that are being developed, access may be unavailable when a mobile device compatible with one wireless technology moves into a wireless network of different technology. This prevents the mobile device from accessing services and limits the mobile device's geographical service area to networks that support a specific wireless technology. For example, a mobile device compliant only with GSM cannot generally access a network based solely on CDMA2000. As the number of differing existing and proposed specifications grows, this limitation may become increasingly problematic.
Therefore, what is needed is a method and system that can provide wireless service to a mobile device regardless of the underlying network technology. It is desirable to enable a mobile device to exchange message contents with a wireless network without concern for possible differences in the technologies involved (e.g., message encoding and decoding schemes). It is also desirable to provide such wireless service without inconveniencing the user.
In one embodiment, a method is provided for transferring information from a network via an interface incompatible with the network to a mobile device that is compatible with both the network and the interface. The method comprises establishing a communication channel between the mobile device and a switch, wherein the switch is accessible to the network and is adapted to send and receive messages compatible with both the network and interface. Information is received from the network and the information is inserted into a first message compatible with the interface. The first message is transferred to the mobile device via the interface.
The present disclosure relates generally to voice and data communications and, more particularly, to a wireless system and method for providing services to a wireless mobile terminal operating in a hybrid wireless network. It is understood, however, that the following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
For the purposes of clarity in the present disclosure, various acronyms are used, the definitions of which are listed below:
Referring to
It is noted that a variety of protocols may be utilized to enable communications to occur through the various components 110-134. For example, some communications may use Signaling System 7 Integrated Services Digital Network (ISDN) User Part (known collectively as “SS7 ISUP”) or Internet Protocol (IP), while others may utilize GPRS Tunneling Protocol U (GTP-U) for user data and GTP-C for signaling.
Referring now to
It is noted that a variety of protocols may be utilized to enable communications to occur through the various components 210-236. For example, some communications may use SS7 ISUP, while others may utilize IP.
Referring now to
The network 300 is structured so as to connect RANs based on different technologies with a single CN. In the present example, the network 300 connects the GSM RAN 104 of
In the present example, the MSC 304 may be connected to a GMSC 306, SCP 308, a HLR 310, an AuC 312, a GGSN 314, and a SMS-C 316. The GMSC 306 may be connected to another network, such as a PSTN 318. This connection may be operable to enable one or both of the mobile devices 102, 202 to communicate with a device on another network, such as a wireline telephone 320 on the PSTN 318. The SCP 308 may be connected to a billing system 322. A PDN 324 may be connected to both the MSC 304 and the GGSN 314. The hybrid MSC 304 enables a mobile terminal in one of the RANs 104 or 204 and certain network entities in the CN 302 to exchange message contents without being obstructed by the differences in the technologies involved (e.g., message encoding and decoding schemes).
In operation, as will be described below in greater detail, the MSC 304 may handle the control and bearer traffic using a centralized call control model for both the GSM RAN 104 and the CDMA2000 RAN 204. Setting-up and controlling a voice or a data call for either of the mobile devices 102, 202 may be done at the MSC 304 as follows. For calls established using the GSM mobile device 102, the MSC 304 operates in a manner similar to the GSM MSC 114 of
This linking may be accomplished by converting messages initiated in the CDMA2000 RAN 204 into GSM messages sent to the CN 302. Likewise, GSM messages initiated by the CN 302 may be converted into CDMA2000 messages sent to the RAN 204. Alternatively, the MSC 304 may create a new message that corresponds to a received message, as is described in greater detail in previously incorporated PCT Application Number WO2002US35500. The linking between the CDMA2000 RAN 204 and the GSM CN 302 may also be accomplished by initiating a function or procedure in one portion of the network 300 using one technology (e.g., CDMA or GSM) upon receiving a certain message from another portion of the network 300 using the other technology (e.g., GSM or CDMA). As will be described below in greater detail, the hybrid MSC 304 may also encapsulate information to facilitate the transfer of information via an otherwise incompatible network or device. Accordingly, the GSM CN 302 may communicate with both the GSM RAN 104 and the CDMA2000 RAN 204, which enables setup calls to be initiated at one of the RANs 104, 204 or at the CN 302.
Referring now to
The MM agent 406 may access mobile user information from a local database such as a visitor location register (VLR) 412. The BSSAP 410 communicates with mobile devices via an interoperability specification (IOS) 414 compliant CDMA BSS (e.g., the BSS 208 of
Referring now to
In step 502, a channel is established between the switch and the MS. This may occur before the MS is authenticated with the network or may occur after such authentication occurs. In step 504, the switch receives information compatible with the first standard from the network This information is inserted by the switch into a first message compatible with the second standard in step 506, and the first message is transferred to the MS via the interface in step 508. The mobile device may then extract the information from the first message. In step 510, the switch receives a second message compatible with the second standard from the MS via the interface. In step 512, the switch converts the second message for compatibility with the first standard for use by the network
In some embodiments, the MS may insert information compatible with the first standard into the second message. The switch would then, upon receipt of the second message, extract the information and relay it to the network. Alternatively, all information in the second message may be compatible with the second standard. The switch would then convert the information from the second standard into corresponding information compatible with the first standard and relay it to the network
Referring now to
In step 608, the hybrid MSC 304 transfers the first CDMA message to the MS 202 via the CDMA interface. The MS 202 extracts and processes the GSM information from the first CDMA message in step 610 and, in step 612, inserts its own GSM information into a second CDMA message. The hybrid MSC 304 receives the second CDMA message from the MS 202 in step 614 and extracts the GSM information in step 616. The extracted GSM information may then processed and transferred per the GSM network standard in step 618.
Referring now to
The call is initiated when the mobile sends a CDMA CM Service Request message to the hybrid MSC 304 via the BSS 208 in step 702. The CM Service Request message contains information about the identification of the mobile device and the call type being requested. In step 704, the hybrid MSC 304 assigns a traffic channel to the mobile device by sending a CDMA Assignment Request message to the CDMA BSS 208. The BSS 208 assigns a radio traffic channel to the mobile device, and upon successful assignment, sends the message CDMA Assignment Complete to the hybrid MSC 304 in step 706. It is noted that the same messages are used in the CDMA RAN and the GSM CN. Accordingly, during these steps, the message converter 416 does very little work Assigning the traffic channel at such an early stage in the call setup procedure enables “ADDS Deliver” CDMA messages to be exchanged between the mobile device and the hybrid MSC 304. This allows the “ADDS Deliver” message to be used to efficiently transfer GSM messages over the CDMA radio interface and avoids the need to convert all of the messages to and from the different protocols.
Once the traffic channel is assigned, the call flow 700 continues with additional activities involved in a mobile originated call setup. From this point forward, the message converter 416 applies a mechanism to link the CDMA radio to the GSM MM/CC agents 406, 408 Applications and Service management layers. In the present example, this is accomplished by inserting the GSM message in the Application Data message field of the “ADDS Deliver” message. This field is based on the CDMA standard and has a flexible length, so it can hold any GSM message used between the mobile device and the GSM MM/CC agents 406, 408 during the call flow 700.
Once the “ADDS Deliver” message is received by the mobile, the mobile device extracts the GSM message and applies the GSM protocol to process the GSM data. The mobile device may then insert GSM information into an “ADDS Deliver” message and sent the CDMA message to the hybrid MSC 304 over the CDMA radio interface. This process enables the hybrid MSC 304 and the mobile device to communicate with each other using GSM messages and information in a manner that is transparent to the CDMA radio interface. This process may be used during the remaining steps of the call setup procedure as follows.
In step 708, the GSM MM/CC agents 406, 408 send an Authentication Request message to the mobile device requesting that the mobile device authenticate itself by sending GSM authentication information. The information is returned by the mobile device in an Authentication response message in step 710. In step 712, the hybrid MSC 304 sends a GSM CM Service Accept message to the mobile device indicating that the request for a call has been accepted. In step 714, the mobile device sends a Setup message to the hybrid MSC 304 that includes detailed call information on the call, such as the called party's number. In step 716, the hybrid MSC 304 sends a Call Proceeding message to the mobile device indicating to the mobile device that the call is in progress. Once the called party is reached, the hybrid MSC 304 sends an Alerting message to the mobile device in step 718 indicating that the called party has been located. When the called party answers the call, the hybrid MSC 304 sends a Connect message to the mobile device in step 720. The mobile device then replies with a Connect_Ack message in step 722 and the call is established between the mobile device and the called party.
At the end of the call, when the mobile device disconnects, a Disconnect message is sent from the mobile device to the hybrid MSC 304 in step 724. The hybrid MSC 304 then sends a Release message back to the mobile device in step 726 when a Release message is received from the called party. In step 728, the mobile device responds with a Release Complete message indicating the call has been successfully released. At this point, the CDMA radio resources are cleared, as indicated by 730.
Referring now to
The call flow 800 begins with step 802 after a call has been received by the hybrid MSC 304 for the mobile device. In step 802, the hybrid MSC 304 sends a CDMA paging request message to the mobile device. The mobile device responds in step 804 by sending a Paging Response message to the hybrid MSC 304. The hybrid MSC 304 then assigns a traffic channel to the mobile device in step 806 by sending a CDMA Assignment Request message to the CDMA BSS 208. In step 808, the BSS 208 assigns a radio traffic channel to the mobile device and, upon successful assignment, sends the message CDMA assignment Complete to the hybrid MSC 304. It is noted that the same messages are used in the CDMA RAN and the GSM CN. Accordingly, during these steps, the message converter 416 does very little work. Assigning the traffic channel at such an early stage in the call setup procedure enables “ADDS Deliver” CDMA messages to be exchanged between the mobile device and the hybrid MSC 304. This allows the “ADDS Deliver” message to be used to efficiently transfer GSM messages over the CDMA radio interface.
Once the traffic channel is assigned, the GSM MM/CC agents 406, 408 continue with additional activities involved in a mobile originated call setup. From this point forward, the message converter 416 applies a mechanism to link the CDMA radio to the GSM MM/CC agents 406, 408 Applications and Service management layers. In the present example, this is accomplished by inserting the GSM message in the Application Data message field of the “ADDS Deliver” message. This field is based on the CDMA standard and has a flexible length, so it can hold any GSM message used between the mobile and the GSM MM/CC agents 406, 408 during the call flow 700.
In step 810, the GSM MM/CC agents 406, 408 send an Authentication Request message to the mobile device requesting that the mobile device authenticate itself by sending GSM authentication information. The mobile device responds in step 812 with the authentication information, which is carried in an Authentication response message. In step 814, the hybrid MSC 304 sends a Setup message to the mobile device indicating that a call is being terminated at the mobile device. The mobile device then sends a Call Conformation message to the hybrid MSC 304 in step 816, indicating that the mobile device is prepared to receive the call. In step 818, the mobile device sends an Alerting message to the hybrid MSC 304 and, in step 820, once the mobile device answers the call, the mobile device sends a Connect message to hybrid MSC 304.
In step 822, the hybrid MSC 304 replies by sending a Connect_Ack message to the mobile device, and the call is established between the mobile device and the calling party. At the end of the call, when the mobile device disconnects, a Disconnect message is sent to the hybrid MSC 304 in step 824. In step 826, the hybrid MSC 304 sends a Release message back to the mobile device after receiving a Release message from the called party. The mobile device responds with a Release Complete message in step 828 indicating the call has been successfully released. At this point, the CDMA radio resources are cleared, as indicated by 830.
In the present disclosure, it is understood that multiple messages may be used to transfer information, even though the above examples illustrate the information being encapsulated in a single message. Furthermore, the exemplary “ADDS Deliver” message used to transfer the GSM data is for illustrative purposes only, and many other types of messages may be used to encapsulate and transfer information on both the uplink and downlink. As such, the present disclosure applies to any message that may be transferred between a mobile device and a network component, such as the hybrid MSC. Furthermore, although certain message fields are described in the present disclosure for purposes of example, it is understood that any field or set of fields may be used to carry information.
Additionally, although a general switching system is used to describe the hybrid MSC, the present disclosure applies to any switching system that may include one or more network entities which have various call control systems. Such a switching system may serve one or more RANs of different technologies, as well as RANs sharing the same technology. The switching system may also link the RANs of various technologies to a CN of a predetermined wireless technology. For instance, a soft switch technology may be used to implement the hybrid MSC. The hybrid MSC may include two parts, each of which is implemented in an independent network entity. One of the two network entities may handle the control part of a call and the other network entity may handle the bearer part. Using soft switch technology to implement the hybrid MSC may provide an increased leverage of equipment investment because the network configuration may be highly scalable.
Although GSM and CDMA are used as examples in the preceding illustrations, it is understood that the disclosure applies to any two or more wireless networks that have the same CN technology but different RAN technologies. Furthermore, even though the CDMA and GSM technologies are used to describe the disclosure, the present disclosure may be applied to any wireless technology that can be used in a hybrid wireless network, and is not limited to these two particular technologies.
While the preceding description shows and describes one or more embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure. For example, it is within the scope of the present disclosure that the BTS, BSS, MSC, and/or mobile device may not exist in the same fashion in other technologies or implementations, but the same functionality may be achieved using other components. Therefore, the claims should be interpreted in a broad manner, consistent with the present disclosure.
This application claims priority from U.S. Provisional Patent Application 60/395,256, filed on Jul. 12, 2002.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US03/22086 | 7/12/2003 | WO | 1/12/2005 |
Number | Date | Country | |
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60395256 | Jul 2002 | US |