Patent Application
20080026755
The accompanying figures where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail the particular method and system for establishing a multiple transfer mode session in accordance with the present invention, it should be observed that the present invention resides primarily in combinations of method steps and apparatus components related to method and system for pre-authentication by collecting the information in the wireless network. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising”, “includes”, “including”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising.
In an embodiment, a method for supporting a Mobile Station (MS) that is capable of Multiple Transfer Mode (MTM) communication in a telecommunications network when the MS is handed over from a MTM non-enabled cell to an MTM enabled cell is provided. The method includes transmitting an information message to the MS, using Fast Access Control Channel (FACCH) signaling. The information message contains data that notifies the MS that it can be using MTM communications and the MS can then proceed into that mode.
In another embodiment, a method for establishing a Dual Transfer Mode (DTM) session between a Mobile Station (MS) and a target Base Transceiver Station (BTS) is provided. Both the MS and the target BTS are DTM-enabled. The method includes a source BTS handing over the MS to the target BTS. The source BTS is DTM non-enabled. The method also includes establishing a Circuit Switched (CS) connection between the MS and the target BTS. Moreover, the method includes a DTM information message being transmitted by the target BTS to the MS by using a transfer channel. The transmission of the DTM information message is carried out by using Fast Associated Control Channel (FACCH) signaling. After receiving the DTM information message, the MS makes a request to the target BTS for DTM.
In yet another embodiment, a system is provided. The system includes a source base transceiver station (BTS), a target BTS, and a mobile station (MS). The source BTS is dual transfer mode (DTM) non-capable whereas the target BTS is DTM capable. The MS is capable of operating in a non-DTM environment as well as a DTM environment. The MS is handed over from the source BTS to the target BTS. The target BTS sends a message over a Fast Access Control Channel (FACCH) to the MS after the handover is completed, to establish DTM.
When the MS 110 is in the cell 102, it acts as a Class B device. In other words, it supports either Packet Switching or Data Switching at a given point, but not both simultaneously. The MS 110 is required to revert to a Class A device on entering the cell 104. This is possible only after the cell 104 informs the MS 110 that the cell 104 can support DTM. The MS 110 must wait to receive a SI6 (System Information broadcast) from the BTS 108 to understand that the DTM enabled cell 104 is DTM capable before initiating or resuming a DTM transaction. This is as per the norm defined by 3GPP specifications.
At step 206, a Circuit Switched (CS) connection is established between the MS 110 and the BTS 108 as a part of the handover process as described above. Establishing the CS connection between the MS 110 and the BTS 108 involves the BSC issuing a Radio Frequency (RF) channel release request to the BTS 106. The RF channel to be released by the BTS 106 is the one associated with the MS 110. After the BTS 106 releases the RF channel, the BTS 106 transmits an acknowledgement to the BSC. Once the RF channel associated with the MS 110 is released by the BTS 106, the BTS 108 is able to reserve an RF channel for the CS connection and associate it with MS 110.
At step 208, the BTS 108 transmits an information message to the MS 110 by using a Traffic Channel (TCH). In an embodiment, transmission of the information message is carried out by the BTS 108 before the transmission of other known system messages. The information message informs the MS 110 that the BTS 108 is capable of supporting DTM. The signaling used to transmit the information message is Fast Associated Control Channel (FACCH) signaling, which transmits data by utilizing frames on TCH for short periods. The FACCH is typically a signaling channel that is used to carry signaling information when there is a voice call. It is not intended to be used for the purpose as disclosed. Hence, signaling speech data is replaced with information message data in FACCH. FACCH signaling is also called in-band signaling. In an embodiment, the information message transmitted is a DTM information message. On receiving the DTM information message, the MS 110 becomes aware that the BTS 108 is capable of DTM operations. By using the FACCH channel, the MS 110 can proceed to take the necessary steps to operate as a DTM device with connections to both the CS and PS sessions without waiting for the SI6 messages as previously required, and as described below.
At step 210, the MS 110 makes a request for DTM to the BTS 108. The MS 110 makes this request over the main DCCH. On receiving the request, the BTS 108 starts the standard DTM call-establishment procedure. The standard DTM call-establishment procedure requires the BTS 108 to prepare a packet data channel. Once the call-establishment procedure is successfully completed, a Temporary Block Flow (TBF) is established between the MS 110 and the BTS 108, and a Packet Switched (PS) connection is established between the MS 110 and the BTS 108. Thereafter, the MS 110 can simultaneously transmit voice and packet data. The method is then terminated at step 212.
In an embodiment, the DTM information message of step 314 is transmitted to the MS 110 by using the main DCCH. The signaling used to transmit the DTM information message is Fast Associated Control Channel (FACCH) signaling. It should be noted that the time that has elapsed between the step 306 and the step 314 ranges between 120-150 ms. In other words, the BTS 108 is able to inform the MS 110 about its capability to support DTM services within 120-150 ms.
After receiving the DTM information in step 314, the MS 110 requests 316 the BTS 108 for DTM. The MS 110 makes this request over the main DCCH. On receiving the request, the BTS 108 starts the standard DTM call-establishment procedure. Once the call-establishment procedure is successfully completed, a Temporary Block Flow is established between the MS 110 and the BTS 108. A Packet Switched (PS) connection is now established between the MS 110 and the BTS 108. The MS 110 can now transmit voice and packet data simultaneously.
The method and system described above for establishing a multiple transfer mode session offers various advantages. The proposed solution offers a significant improvement in DTM establishment time. The time saving can be between 570 ms to 2250 ms, as compared to the solution recommended by the 3GPP specification. This solution provides consistent performance improvements for various scenarios, and improves the end user's perception of the data service while using DTM.
In an embodiment of the invention, the BTS 108 may be aware of a previous DTM session between the BTS 108 and the MS 110 because a non-zero value exists for the packet session that is established as described above. The non-zero value is a part of the DTM information that is sent in step 314.
It will be appreciated the client described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the client described herein. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method to perform {accessing of a communication system}. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein.
It is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
In the foregoing specification, the invention and its benefits and advantages have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
