The exemplary and non-limiting embodiments of this invention relate generally to wireless communications systems and, more specifically, relate to connection setup methods, apparatus and computer program products for use in a digital wireless communications network.
The architecture of the Circuit Switched (CS) and Packet Switched (PS) call establishment in Wideband Code Division Multiple Access (WCDMA) networks requires first that a Radio Resource Control (RRC) connection establishment between the User Equipment (UE) and the Radio Network Controller (RNC) as shown in
If no PDP context is active, the UE continues with the PDP (Packet Data Protocol) context activation procedure to activate the PDP context (or setup for CS voice) as shown in
It should be noted that as currently specified the service request is carried within the RRC: Initial Direct transfer and RANAP: Initial UE Message over Uu and Iu interfaces as transparent NAS-PDU (Non-Access Stratum-Packet Data Unit). The Uu interface is the interface between the UTRAN and the UE, while the Iu is the interconnection point between the RNC or a BSC (Base Station Controller) and 3G (Third Generation) core network (CN). RANAP (Radio Access Network Application Part) is the Radio Network Layer signaling protocol for the Iu interface (e.g., between the UTRAN and Core Network). The RANAP resides in the UTRAN and the Core Network (CN).
As can be seen, since the RRC connection setup and service request are performed sequentially, the current specifications inherently containing the setup delay of each of these sequential procedures. It can be shown that the RRC connection setup delay can be approximately 500 milliseconds (ms) and the Service Request setup delay can be approximately 70 ms. If one includes PDP context activation of about 1200 ms, it can be appreciated that even if using more optimized signaling transfer, such as by utilizing High Speed Uplink Packet Access (HSUPA) and High Speed Downlink Packet Access (HSDPA) for the Signaling Radio Bearers (SRBs), since these procedures are performed in sequence, achieving further delay reductions are extremely difficult.
Recent observations from commercial WCDMA networks have shown that this sequence of different procedures can introduce an unacceptable amount of delay during CS and PS call establishment.
It is known that in the GSM (Global System for Mobile communication) CS, mobile-originated call establishment case, the service request message (CM SERVICE REQUEST) is sent piggy-backed, i.e., contained in the GSM Level 2 (L2) (LAPDm; Link Access Protocol on the D-Channel, modified) messages requesting the establishment of the L2 link (which in turn, after successfully established, creates a successful Radio Resource connection). For PS services, however, the situation is different, as for any signaling or link establishment between the MS and the network a TBF (temporary block flow) establishment procedure takes place. This establishment procedure itself does not carry any Layer 3 (L3) signaling or service request. The inventors have realized that the call establishment process for PS (and CS) services is not as efficient as the process could be.
In an exemplary embodiment, a method is disclosed that includes, at a user equipment, combining a message requesting the radio resource connection and a message requesting at least one service into a single message. The method also includes transmitting the single message from the user equipment to a network element in a wireless network.
In another exemplary embodiment, a user equipment is disclosed that includes a transceiver and processing logic coupled to the transceiver. The processing logic is configured to combine a message requesting a radio resource connection and a message requesting at least one service into a single message. The processing logic is further configured to cause the transceiver to transmit, using the transceiver, the single message from the user equipment to a network element in a wireless network.
In yet another exemplary embodiment, a computer program product is disclosed that tangibly embodies a program of machine-readable instructions executable by one or more data processors to perform operations. The operations include, at a user equipment, combining a message requesting the radio resource connection and a message requesting at least one service into a single message. The operations also include causing the single message to be transmitted from the user equipment to a network element in a wireless network.
In a further exemplary embodiment, a method is disclosed that includes receiving, from a user equipment, a single message including both a message requesting the radio resource connection and a message requesting at least one service. The method includes, in response to the message requesting the radio resource connection, performing radio resource control connection establishment for the user equipment in order to establish the radio resource control connection between the user equipment and at least one of a plurality of network elements of a wireless network. The method also includes, in response to the message requesting the at least one service, performing service request procedures for the user equipment, wherein at least part of the radio resource control connection establishment and at least part of the service request procedures are performed in parallel.
In an additional exemplary embodiment, a wireless network is disclosed that includes a transceiver and processing logic coupled to the transceiver. The processing logic is configured to receive, from the transceiver and from a user equipment, a single message including both a message requesting a radio resource connection and a message requesting at least one service. The processing logic is further configured, in response to the message requesting the radio resource connection, to perform radio resource control connection establishment for the user equipment in order to establish the radio resource control connection between the user equipment and at least one network element of a wireless network. The processing logic is additionally configured, in response to the message requesting the at least one service, to perform service request procedures for the user equipment, wherein at least part of the radio resource control connection establishment and at least part of the service request procedures are performed by the processing logic in parallel.
In yet another exemplary embodiment, a computer program product is disclosed that tangibly embodies a program of machine-readable instructions executable by one or more data processors to perform operations. The operations include receiving from a user equipment a single message including both a message requesting the radio resource connection and a message requesting at least one service. The operations also include, in response to the message requesting the radio resource connection, causing radio resource control connection establishment to be performed for the user equipment in order to establish a radio resource control connection between the user equipment and at least one network element of a wireless network. The operations further include, in response to the message requesting the at least one service, causing service request procedures for the user equipment to be performed, wherein at least part of the radio resource control connection establishment and at least part of the service request procedures are performed in parallel.
In another exemplary embodiment, a method is disclosed that includes, at a user equipment, combining a message requesting a radio resource connection and a message requesting at least one service into a single message, and transmitting the single message from the user equipment to a first network element in a wireless network. The method also includes, at the first network element, receiving the single message and, in response to the message requesting the radio resource connection, and performing radio resource control connection establishment for the user equipment in order to establish a radio resource control connection between the user equipment and at least one of a plurality of network elements of a wireless network. The method further includes, at a second network element in the wireless network, in response to the message requesting the at least one service, performing service request procedures for the user equipment, wherein at least part of the radio resource control connection establishment and at least part of the service request procedures are performed in parallel.
The foregoing and other aspects of embodiments of this invention are made more evident in the following Detailed Description of Exemplary Embodiments, when read in conjunction with the attached Drawing Figures, wherein:
As described above, in the GSM CS, mobile-originated call establishment case, the service request message (CM SERVICE REQUEST) is sent piggy-backed, i.e., contained in the GSM Level 2 (L2) (LAPDm) messages requesting the establishment of the L2 link (which in turn, after successfully established, creates a successful Radio Resource connection). The request for establishment of the L2 link is a request to establish one or more logical channels and the request is communicated using L2 messaging. In GSM CS, mobile-originated call establishment case, the UE already has a radio channel (e.g., frequency and timeslot) and therefore the UE already has a “radio link” prior to when the CM SERVICE REQUEST message is communicated to set up a logical channel. After a number of different steps, a completion of an RR connection occurs. Although GSM and WCDMA are different systems, in WCDMA, the L2 layer includes Radio Link Control (RLC).
By contrast, in exemplary embodiments of the disclosed invention, Layer 3 (L3) signalling, Radio Resource Control (RRC) signalling, is used. Thus, a radio resource connection is created in response to an RRC: Connection Request message. No such radio resource connection is created in the GSM CS, mobile-originated call establishment case, as an LAPDm connection creates a logical channel and not a radio resource connection.
Reference is made first to
Note that the PS CN 16 may comprise the Serving Gateway Support Node (SGSN) and the Gateway GPRS (General Packet Radio Service) Support Node (GGSN) shown in
In general, the various embodiments of the UE 10 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.
The embodiments of this invention may be implemented by computer software executable by the DP 10A of the UE 10 and the other DPs, or by hardware, or by a combination of software and hardware.
The MEMs 10B, 12B, 14B and 16B may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 10A, 12A, 14A, and 16A may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPS) and processors based on a multi-core processor architecture, as non-limiting examples.
It should be noted that while the Node B 12 is shown containing the PROG 12C, in order to practice this invention the PROG 12C may not need to be modified from a conventional Node B program. Further, it will be shown below that in at least some embodiments of this invention the PROG 16C of the CN 16 may not need modification so as to operate with the enhanced UE/UTRAN signaling in accordance with the invention.
As can be seen in
It should be noted that, depending on implementation, one or more services could be requested using a service request message. As both messages are sent using a single message from the UE 10 to the wireless network, the RRC connection establishment and the service request procedures are enabled to be performed in a parallel manner in the UTRAN 20 and PS CN 16, respectively. This parallel execution of these procedures beneficially removes the RRC connection establishment delay, which is currently inherent in the specifications, from the total connection setup delay. Thus, in an exemplary embodiment, CN procedures to activate PDP context are performed simultaneously with UTRAN 20 procedures to establish the RRC connection. It is noted that an Initial Direct Transfer message is used to initiate a signalling connection based on indication from upper layers and to transfer a NAS message. The RRC Connection Request message is the first message transmitted by the UE 10 when setting up an RRC connection to the network.
In a case where the network (e.g., UTRAN 20) supports this feature of parallel execution of the RRC connection establishment request and service request procedures, the UTRAN 20 indicates this capability in, for example, System Information Broadcast (SIB) messages to the UE 10. In this case the UE 10 establishes a PS or CS connection to the network by sending the RRC Connection Request message to the UTRAN 20. This message contains also the NAS: Service Request message, which is considered as a transparent bit string for radio protocols in similar manner as is done for a RRC: Initial Direct Transfer message (that currently contains the NAS service request message as a transparent container).
The conventional RRC Connection Request message can be found in tabular format in subclause 10.2.39 of 3GPP TS 25.331 (e.g., 3GPP TS 25.331, version 6.6.0, Release 6, 6-2005). This section states that the RRC Connection Request is the first message transmitted by the UE when setting up an RRC Connection to the network. The conventional Initial Direct Transfer can be found in sub-clause 10.2.16c of 3GPP TS 25.331, where it can be seen that the Initial Direct Transfer contains a NAS message, described in section 10.3.1.8. The NAS message contains the service request message. Section 10.2.16c states that the Initial Direct Transfer message is used to initiate a signalling connection based on indication from the upper layers and to transfer a NAS message. The Abstract Syntax Notation One (ASN.1) coding, used for RRC messages, is provided in section 11 of 3GPP TS 25.331.
A first exemplary embodiment of a new message format for the RRC Connection Request (e.g., inclusion of an Initial Direct Transfer message) is shown in
One advantage of this first embodiment is that the first embodiment is backwards compatible, and no new combination message is required (i.e., legacy networks that have not implemented this embodiment may simply ignore the BIT STRING).
However, the UE 10 does not know if the RNC 14 has decoded the message 50, so thus the UE 10 may still need to send the Initial Direct Transfer on its own once the RRC connection has been setup. This occurs in Step 340, when the UE 10 sends a second Initial Direct Transfer message having a service request. It is noted that Step 340 is performed in response to the message in Step 310 not being received. Step 340 allows for backward compatibility. In this example, the UTRAN 20 indicates support of parallel execution of radio resource control connection establishment and service request procedures through the use of the message in Step 310. If the message in Step 310 is not received, the UE 10 needs to fallback to a Rel99 (Release 99) solution, where the IDT is only sent after RRC Connection Setup Complete (Step I). As for a Rel99 solution, 3GPP TS 25.331, section 8.1.3 (e.g., 3GPP TS 25.331, version 6.6.0, Release 6, 6-2005), shows an RRC connection establishment procedure. The IDT procedure is shown in TS 25.331, section 8.1.8. To avoid passing the Initial Direct Transfer message information twice, the RNC 14 would need to ignore the second message. This occurs in Step 350, where the RNC 14 ignores an Initial Direct Transfer message after the message 50. An amount of coding in ASN.1 may also be needed.
A second exemplary embodiment of a new message format for the RRC Connection Request (e.g., creation of enhanced RRC Connection Request) is shown in
In this embodiment, the UTRAN 20 may broadcast a capability bit in system information for informing the UE 10 that the UE 10 is permitted to transmit an “enhanced RRC Connection Request” 52. For instance, see the capability bit 312 in System Information Broadcast (SIB) 311 of the message 310, indicating capability of parallel execution of radio resource control connection establishment and service request procedures, in
When the UTRAN 20 receives the RRC Connection Request message (Step A), the UTRAN 20 processes the information elements (IEs) as is specified by current standards. For instance, in the example of
It is noted that if the RRC connection setup is performed to the CELL_DCH state, a security mode command can be sent after L1 synchronization to the UE via DCH following the RB (Radio Bearer) setup procedure. If the CELL_FACH state is utilized, the security mode command and the RB setup can be sent after the RRC connection setup. As shown in
In principle, an RRC: Cell Update message could also contain the NAS message (i.e., the IDT message including a CM Service Request message) as this would speed up the CS call setup in the case where the UE 10 is already in the RRC Connected state in the URA/CELL_PCH state. Instead of waiting to use Cell Update and Cell Update Confirm signaling procedures before being able to send the CM Service Request to the CS CN 16, the inclusion of the CM Service Request message to the RRC: Cell Update message (e.g., a portion of which contains the original RRC: Cell Update message) allows the Cell Update and Cell Update Confirm signaling procedures to be performed in parallel with the RRC cell update procedures.
Advantages that are realized by the use of the non-limiting embodiments of this invention include, but are not limited to, a more rapid call setup for CS and PS connections when the UE 10 is in the idle mode; changes can be limited to only the RRC Connection Request message (Step A of
It can be noted that fitting the RRC Connection Request message and the Service Request in one transport block (TB) may require that some optimization be made to the Service Request message, which may then require a corresponding modification to the PS/CS CN 16.
It can be further noted that even though the exemplary embodiments of this invention are related to current WCDMA radio access and PS and CS core networks, they may also be applicable for other networks, such as for the 3.9G network architecture depending on implementation.
Based on the foregoing it should be apparent that the exemplary embodiments of this invention provide a method, apparatus and computer program product(s) to combine the RRC: RRC Connection Request message and the RRC: Initial Transfer message, which contains the Service Request message sent by the UE 10 to the PS CN 16 (e.g., the CM service request is sent to the CS CN 16), where both messages are sent in a single message from UE 10 to the network, and where both RRC connection establishment and service request procedures are performed in a parallel manner in the UTRAN 20 and the PS/CS CN 16, respectively, so as to reduce the overall connection setup delay of the PS or CS connection, by performing parallel processing for setting up the RRC connection between the UE 10 and the UTRAN 20, and the Service Request between the UE 10 and the PS/CS CN 16.
In general, the various embodiments may be implemented in hardware (e.g., special purpose, circuits) or software or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in software (e.g., firmware) which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware (e.g., special purpose circuits, general purpose hardware or a controller or other computing device) or software (e.g., firmware), or some combination thereof.
Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logical level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.
Programs, such as those provided by Synopsys, Inc. of Mountain View, Calif. and Cadence Design, of San Jose, Calif. automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre-stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or “fab” for fabrication.
As an example,
Various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications of the teachings of this invention will still fall within the scope of the non-limiting embodiments of this invention.
Furthermore, some of the features of the various non-limiting embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.
The present application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional patent application No. 60/709,509, filed on Aug. 19, 2005.
Number | Date | Country | |
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60709509 | Aug 2005 | US |