Radio resource management architectures for internet protocol based radio access networks with radio resource control in base stations

CROSS REFERENCE TO RELATED APPLICATIONS

0001The present application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 11/405,390, filed Apr. 17, 2006, entitled “METHODS AND APPARATUS FOR RESOURCE MANAGEMENT ARCHITECTURES FOR INTERNET PROTOCOL BASED RADIO ACCESS NETWORKS,” the entire contents of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

0002Embodiments of the present invention relate to the field of wireless networks, and more specifically, to methods and apparatus for radio resource management (RRM) architectures for Internet Protocol (IP) based radio access networks.

BACKGROUND

0003Radio resource management in IP based radio access networks involves procedures that provide decision support for IP based radio access networks, such as, for example, Worldwide Interoperability for Microwave Access (WiMAX) networks, and their associated functions. Some of these functions include, for example, mobile client admission control, i.e., ascertaining that required radio resources are available at a potential target base station (BS) before handover (HO) of service; service flow admission control, i.e., creation or modification of existing/additional service flows for an existing MS in the network; selection of values for admitted and active quality of service (QoS) parameter sets for service flows; load control, which manages situations where system load exceeds the threshold and some counter-measures need to be taken to get the system back to feasible load; and HO preparation and control for improvement and maintenance of overall performance indicators (for example, RRM may assist in system load balancing by facilitating selection of the most suitable base station during a HO of service).

BRIEF DESCRIPTION OF THE DRAWINGS

0004Embodiments of the present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.

0005<figref idref="DRAWINGS">FIG. 1</figref> is a schematic diagram of exemplary Internet Protocol (IP) based radio access networks incorporated with the teachings of the present invention, in accordance with various embodiments;

0006<figref idref="DRAWINGS">FIG. 2</figref> is a schematic diagram of exemplary RRM architecture for access service networks incorporated with the teachings of the present invention, in accordance with various embodiments;

0007<figref idref="DRAWINGS">FIG. 3</figref> is a schematic diagram of exemplary RRM architecture for access service networks incorporated with the teachings of the present invention, in accordance with various embodiments;

0008<figref idref="DRAWINGS">FIG. 4</figref> is a schematic diagram of exemplary RRM architecture for access service networks incorporated with the teachings of the present invention, in accordance with various embodiments; and

0009<figref idref="DRAWINGS">FIG. 5</figref> is a block diagram representation of an example processor system that may be used to practice various aspects of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

0010In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments in accordance with the present invention is defined by the appended claims and their equivalents.

0011Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent.

0012The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of embodiments of the present invention.

0013For the purposes of the present invention, the phrase “A/B” means A or B. For the purposes of the present invention, the phrase “A and/or B” means “(A), (B), or (A and B)”. For the purposes of the present invention, the phrase “at least one of A, B, and C” means “(A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C)”. For the purposes of the present invention, the phrase “(A)B” means “(B) or (AB)” that is, A is an optional element.

0014The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present invention, are synonymous.

0015Embodiments of the present invention provide methods and apparatus for efficient radio resource management (RRM) architecture for Internet Protocol (IP) based radio access networks. The methods and systems described herein are not limited in this regard.

0016To provide a clear and understandable description of embodiments of the present invention, a brief description of Internet Protocol (IP) based radio access networks (RANs) is provided below. Additionally, examples of methods and apparatus for RRM architectures are described with reference to RANs. It should be understood that principles and techniques of embodiments of the present invention may be employed for RRM architectures of RAN networks such as, for example but not limited to, Worldwide Interoperability Microwave Access (WiMAX) networks, Wireless Fidelity (Wi-Fi) networks, Third Generation (3G) cellular networks and Ultra-wideband (UWB) networks. The IP based RANs of <figref idref="DRAWINGS">FIG. 1</figref> are illustrated and described as WiMAX RANs for simplicity. Additionally, although some of the examples are described with respect to standards developed by Institute of Electrical and Electronic Engineers (IEEE), the methods and systems disclosed herein are not so limited, and are readily applicable to many specifications and/or standards developed by other special interest groups and/or standard development organizations (e.g., Wireless Fidelity (Wi-Fi) Alliance, Worldwide Interoperability for Microwave Access (WiMAX) Forum, Infrared Data Association (IrDA), Third Generation Partnership Project (3GPP), Ultra-wideband (UWB) Forum, etc.).

0017<figref idref="DRAWINGS">FIG. 1</figref> illustrates simplified exemplary IP based RANs incorporated with the teachings of the present invention in accordance with various embodiments and Radio Resource Management (RRM) architecture. A first WiMAX RAN <b>1</b> (<b>100</b>) is illustrated that includes a gateway (GW) <b>106</b> communicatively coupled to base stations <b>110</b>, <b>112</b> and <b>114</b> via links <b>124</b>, <b>126</b> and <b>128</b>, respectively. A second WiMAX RAN <b>2</b> (<b>102</b>) is illustrated that includes a GW <b>108</b> communicatively coupled to base stations (BS) <b>116</b> and <b>118</b> via links <b>130</b> and <b>132</b>, respectively. Each GW includes an omnidirectional antenna (not shown). A third WiMAX RAN <b>3</b> (<b>104</b>) is illustrated that does not include a gateway but does include two base stations <b>120</b> and <b>122</b>.

0018Each base station includes an RRM component in the form of a radio resource agent (RRA). RANs <b>100</b>, <b>102</b> and <b>104</b> also include another RRM component in the form of at least one radio resource controller (RRC), which may reside in a base station or in a GW depending upon the RAN deployment profile. Thus, in the exemplary embodiment illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, RANs <b>100</b> and <b>102</b> include a RRC within their GWs <b>106</b> and <b>108</b>, respectively, while RAN <b>104</b> includes its RRC within base station <b>120</b>. In addition, each RAN may include multiple gateways.

0019In one example, mobile client devices (MCD) <b>154</b> access the networks (via an appropriate base station) using the Physical Layer (PHY) and Media Access Control Layer (MAC) features defined by the IEEE 802.16 family of standards (e.g., the IEEE std. 802.16-2004, published Sep. 18, 2004; the IEEE std. 802.16e, published Feb. 28, 2006; etc.). Exemplary MCDs include notebook computers and hand-held wireless devices (e.g., personal digital assistants (PDAs), pocket PCs, cellular phones supporting 802.16 links, etc.).

0020To support station-side operations, each MCD <b>154</b> provides an appropriate RAN interface, such as depicted by a PCMCIA card <b>158</b> for a notebook computer. Optionally, the RAN wireless interface may be built into the MCD <b>154</b>. Each MCD is illustrated communicatively coupled to a base station via a link <b>156</b>.

0021In general, an MCD <b>154</b> may access a RAN via some form of subscription service offered by a RAN service provider, although some RAN services might be provided free of charge, e.g., University campus, city coverage, etc. As such, GWs <b>106</b> and <b>108</b> are depicted as being communicatively coupled to and managed by a WiMAX core network <b>136</b> via links <b>138</b> and <b>140</b>, respectively. Additionally, GWs <b>106</b> and <b>108</b> may be communicatively coupled to one another as depicted by link <b>134</b>. RAN <b>104</b> is communicatively coupled to the WiMAX core network via its base stations <b>120</b> and <b>122</b> as depicted by link <b>142</b>. It will be understood that the coupling between a given GW and WiMAX core network <b>136</b> may be via a dedicated link (e.g., private trunk or the like), or through another communication means, such as via IP backbone network <b>144</b>, which includes multiple network elements <b>146</b> (e.g., backbone switches and routers), as depicted by links <b>135</b> and <b>145</b>. WiMAX core network <b>136</b> is communicatively coupled to IP backbone network <b>144</b> via link <b>143</b>.

0022A Voice over IP (VoIP) provider <b>148</b> is illustrated communicatively coupled to IP backbone <b>144</b> to enable phone calls to be carried over Internet infrastructure using a packetized transport. For illustrative purposes, the VoIP facilities depicted in <figref idref="DRAWINGS">FIG. 1</figref> is represented by a VoIP provider network <b>148</b>, a telecommunications (telco) network <b>150</b>, and a telephone <b>152</b> (or other suitable device such as, for example, desktop computer, notebook computer and hand-held wireless devices (e.g., personal digital assistants (PDAs), pocket PCs, cellular phones)).

0023<figref idref="DRAWINGS">FIG. 2</figref> schematically illustrates general RRM architecture for RANs that incorporates the teachings of the present invention in accordance with various embodiments. As may be seen, a first RAN <b>200</b> includes an RRC <b>202</b> within a RAN gateway and RRAs <b>204</b>, <b>205</b> within RAN base stations (BS). A second RAN <b>206</b> includes RRC <b>208</b> within a RAN gateway and RRAs <b>210</b>, <b>212</b> and <b>214</b> within RAN base stations (BS). RRC <b>202</b> communicates with RRC <b>208</b> and RRAs <b>204</b>, <b>205</b> of its own RAN. RRC <b>208</b> communicates with RRC <b>202</b> and RRAs <b>210</b>, <b>212</b> and <b>214</b>. The interfaces over which the RRM messages are sent are IP based.

0024<figref idref="DRAWINGS">FIG. 3</figref> schematically illustrates exemplary RANs <b>300</b> and <b>302</b> in accordance with various embodiments of the present invention, wherein RRCs are included within at least one base station. RAN <b>300</b> includes base stations <b>304</b>, <b>306</b> and <b>308</b>, while RAN <b>302</b> includes base stations <b>310</b> and <b>312</b>. Gateways <b>314</b> and <b>316</b> are also included within RANs <b>300</b> and <b>302</b>, respectively. As may be seen, in this embodiment, base stations <b>302</b>, <b>304</b> and <b>312</b> each include an RRC and RRA, while base stations <b>306</b> and <b>310</b> each include an RRA. Gateways <b>314</b> and <b>316</b> each include an RRM relay. Those skilled in the art will understand that a different number of base stations may be included in the networks if desired, each of which may include an RRC and/or an RRA. Additionally, each network may include more than one gateway, each of which will include an RRM relay in this exemplary embodiment.

0025With RRAs and RRCs co-located within some base stations, the RRM relay is provided within a gateway of the RAN in order to facilitate the RRC to RRC and RRC to RRA communications within and between RANs over standard reference interfaces. With such a model, RRM primitives may be supported in an effective manner between the RRCs and the RRAs, both intra- and inter-RAN when an RRC and an RRA are co-located in base stations, and when only an RRA is located within a base station.

0026For example, when RRC in base station <b>304</b> is going to communicate with RRC in base station <b>306</b> within RAN Network <b>300</b>, the RRC within base station <b>304</b> will communicate with the RRM relay within gateway <b>314</b>, which will pass along the communication to the RRC within base station <b>306</b>. Likewise, if the RRC within base station <b>304</b> wishes to communicate with the RRA within base station <b>308</b>, the RRC will communicate with the RRM relay within gateway <b>314</b>, which will pass along the communication to the RRA. If the RRC within base station <b>304</b> wishes to communicate with an RRC or RRA in RAN <b>302</b>, then the RRC within base station <b>304</b> will communicate with the RRM relay within gateway <b>314</b>, which passes along the communication to the RRM relay within gateway <b>316</b>, which passes along the communication to either the RRC within base station <b>312</b> (which may pass on the communication to the RRA within the base station <b>312</b> if necessary) or the RRA within base station <b>310</b>. Likewise, if an RRA wishes to communicate with an RRC or another RRA, the RRA communicates with an appropriate RRC or RRM relay, which passes on the communication down the line as appropriate.

0027Turning to <figref idref="DRAWINGS">FIG. 4</figref>, RAN <b>400</b> includes RAN gateways <b>402</b> and <b>404</b> as well as base stations <b>406</b>, <b>408</b>, <b>410</b>, <b>412</b> and <b>414</b>. RAN <b>400</b> is organized in a manner similar to the network illustrated in <figref idref="DRAWINGS">FIG. 2</figref> and thus, RAN gateways <b>402</b> and <b>404</b> include RRCs, while base stations <b>406</b>, <b>408</b>, <b>410</b>, <b>412</b> and <b>414</b> include RRAs. If RAN <b>300</b> or <b>302</b> wish to communicate with RAN <b>400</b>, then the appropriate RRM relay within gateway <b>314</b> or <b>316</b> will communicate with the appropriate RRC within either RAN gateway <b>402</b> or RAN gateway <b>404</b>. The communication may be direct or indirect, i.e., the RRM relay may communicate with gateway <b>402</b>, which passes the communication to gateway <b>404</b>.

0028Communications received from the RRM relays at the RAN gateways <b>402</b> and <b>404</b> are passed to the base stations as appropriate. For example, if the RRC within base station <b>310</b> wishes to communicate with the RRA in base station <b>406</b>, the RRC in base station <b>310</b> will communicate with the RRM relay in RAN gateway <b>316</b>, which will communicate with the RRC in RAN gateway <b>402</b>, which will communicate with the RRA in base station <b>406</b>. Likewise, if an RRM component in RAN <b>400</b> wishes to communicate with an RRM component in RANs <b>300</b> or <b>302</b>, the RRM component in RAN <b>400</b> communicates with an appropriate RRC or appropriate RRM relay as illustrated in <figref idref="DRAWINGS">FIG. 4</figref>, which passes on the communication down the line as appropriate.

0029Examples of key message primitives for RANs include a “base station spare capacity request,” which is sent to the base station from which the spare capacity report is needed and a “Per-base station spare capacity report,” which is sent in response to a “base station spare capacity request.” These reports are indexed by each base station's identification (ID) and indicate the radio resources available at the particular base station, e.g. as a tool for base station selection during network entry or handover. Such reporting may be solicited or unsolicited. Such reports are sent from RRA to RRC, as well as between RRCs such that all interested RRCs may have information on current spare capacity of the base stations for which they are responsible, or, of neighboring base stations in other RANs.

0030Other primitives include a “Per MCD physical (PHY) layer report” request, which relates to, for example, a request for the radio resources used by the service flows currently active in the MCD and is requested by any base station from the base station serving an MCD, and a “Per MCD PHY report response,” which is the response to the “Per MCD PHY layer report” and is sent from the base station serving the MCD to the requesting base station.

0031Another primitive includes a “base station radio resource status update,” which is generated from RRC to RRA to propose a change of a broadcasted “neighbor advertisement message” on the airlink (for handover purposes) from this base station based on the load from neighboring base stations.

0032The contents of a “base station spare capacity request” may be used at the time of handoff of service for an MCD before the handoff occurs. The base station currently serving the MCD may request this report from some or all of the base stations in a neighbor list of base stations. A neighbor list generally identifies base stations that are neighbors to a particular base station for various purposes such as, for example, handover of service. Additionally, a “Per MCD PHY report response” may be sent in an unsolicited manner from the base station serving the MCD to all the other base stations in the neighbor list during handover preparation or it may be sent from the serving base station to a target base station in response to a “Per MCD physical (PHY) layer report” from the target base station (once the target base station is chosen for handover of service). The contents of a “Per MCD PHY report response” may be used to prune the neighbor list before the neighbor advertisement message is sent on the airlink. This may be sent from an RRC located in the network gateway or a base station to all or some of the base stations in the network.

0033Many of the RRM messages described above are intended for multiple recipients. A beneficial manner for delivery of the messages intended for multiple recipients (with minimal message copy transmissions) is to use Internet protocol (IP) multicasting. IP multicasting techniques are used to provide communication between radio resource controllers (e.g., gateways) and radio resource agents (e.g., base stations) in a network. IP multicasting involves sending a single message from a source node in a network to a plurality of destination nodes. Typically, a unique IP address is assigned to a predetermined group of communication nodes in the network. A message may then be delivered to that IP address and every node that is a part of the group is able to read the message.

0034To utilize IP multicasting during RAN operations in a RAN, a number of multicast groups may be formed and maintained in the network. Each of the multicast groups may be assigned a unique IP multicast address. An RRC may then transmit an RRM message as an IP multicast message to a corresponding multicast group when information is needed or being provided. The IP multicast message is sent via IP backbone <b>144</b>.

0035Various procedures are defined within the Requests for Comments (RFCs) of the Internet Engineering Task Force (IETF) that may be used to perform various tasks associated with various embodiments of the present invention. For example, RFCs exist for procedures to create multicast groups, to allow entities (e.g., base stations, PCs, etc.) to join and leave multicast groups, to perform packet exchanges within multicast groups, and so on. An example is RFC 966 (1985). These procedures may be used in various embodiments of the invention. Other procedures may alternatively be used. In at least one embodiment of the invention, the base stations in a multicast group use a shortest path tree based multicast distribution tree for the transfer of multicast messages. By using a shortest path tree based multicast distribution tree, reduced delays are incurred in the transfer of messages between the multicast members.

0036Thus, the communications within and between RANs <b>300</b>, <b>302</b> and <b>400</b> and their various components may be handled as unicast transmissions or may be handled as IP multicasts.

0037<figref idref="DRAWINGS">FIG. 5</figref> is a block diagram of an example processor system <b>2000</b> adapted to implement the methods and apparatus disclosed herein, in accordance with various embodiments. The processor system <b>2000</b> may be a desktop computer, a laptop computer, a handheld computer, a tablet computer, a PDA, a server, an Internet appliance, and/or any other type of computing device.

0038The processor system <b>2000</b> illustrated in <figref idref="DRAWINGS">FIG. 5</figref> may include a chipset <b>2010</b>, which includes a memory controller <b>2012</b> and an input/output (I/O) controller <b>2014</b>. The chipset <b>2010</b> may provide memory and I/O management functions as well as a plurality of general purpose and/or special purpose registers, timers, etc. that are accessible or used by a processor <b>2020</b>. The processor <b>2020</b> may be implemented using one or more processors, Wireless Personal Area Network (WPAN) components, Wireless Local Area Network (WLAN) components, Wireless Metropolitan Area Network (WMAN) components, Wireless Wide Area Network (WWAN) components, and/or other suitable processing components. For example, the processor <b>2020</b> may be implemented using one or more of the Intel® Core™ technology, Intel® Pentium® technology, the Intel® Itanium® technology, the Intel® Centrino™ technology, the Intel® Core™ Duo technology, the Intel® Xeon™ technology, and/or the Intel® XScale® technology. In the alternative, other processing technology may be used to implement the processor <b>2020</b>. The processor <b>2020</b> may include a cache <b>2022</b>, which may be implemented using a first-level unified cache (L1), a second-level unified cache (L2), a third-level unified cache (L3), and/or any other suitable structures to store data.

0039The memory controller <b>2012</b> may perform functions that enable the processor <b>2020</b> to access and communicate with a main memory <b>2030</b> including a volatile memory <b>2032</b> and a non-volatile memory <b>2034</b> via a bus <b>2040</b>. The volatile memory <b>2032</b> may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM), and/or any other type of random access memory device. The non-volatile memory <b>2034</b> may be implemented using flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), and/or any other desired type of memory device.

0040The processor system <b>2000</b> may also include an interface circuit <b>2050</b> that is coupled to the bus <b>2040</b>. The interface circuit <b>2050</b> may be implemented using any type of interface standard such as an Ethernet interface, a universal serial bus (USB), a third generation input/output (3GIO) interface, and/or any other suitable type of interface.

0041One or more input devices <b>2060</b> may be connected to the interface circuit <b>2050</b>. The input device(s) <b>2060</b> permit an individual to enter data and commands into the processor <b>2020</b>. For example, the input device(s) <b>2060</b> may be implemented by a keyboard, a mouse, a touch-sensitive display, a track pad, a track ball, an isopoint, and/or a voice recognition system.

0042One or more output devices <b>2070</b> may also be connected to the interface circuit <b>2050</b>. For example, the output device(s) <b>2070</b> may be implemented by display devices (e.g., a light emitting display (LED), a liquid crystal display (LCD), a cathode ray tube (CRT) display, a printer and/or speakers). The interface circuit <b>2050</b> may include, among other things, a graphics driver card.

0043The processor system <b>2000</b> may also include one or more mass storage devices <b>2080</b> to store software and data. Examples of such mass storage device(s) <b>2080</b> include floppy disks and drives, hard disk drives, compact disks and drives, and digital versatile disks (DVD) and drives.

0044The interface circuit <b>2050</b> may also include a communication device such as a modem or a network interface card to facilitate exchange of data with external computers via a network. The communication link between the processor system <b>2000</b> and the network may be any type of network connection such as an Ethernet connection, a digital subscriber line (DSL), a telephone line, a cellular telephone system, a coaxial cable, etc.

0045Access to the input device(s) <b>2060</b>, the output device(s) <b>2070</b>, the mass storage device(s) <b>2080</b> and/or the network may be controlled by the I/O controller <b>2014</b>. In particular, the I/O controller <b>2014</b> may perform functions that enable the processor <b>2020</b> to communicate with the input device(s) <b>2060</b>, the output device(s) <b>2070</b>, the mass storage device(s) <b>2080</b> and/or the network via the bus <b>2040</b> and the interface circuit <b>2050</b>.

0046While the components shown in <figref idref="DRAWINGS">FIG. 5</figref> are depicted as separate blocks within the processor system <b>2000</b>, the functions performed by some of these blocks may be integrated within a single semiconductor circuit or may be implemented using two or more separate integrated circuits. For example, although the memory controller <b>2012</b> and the I/O controller <b>2014</b> are depicted as separate blocks within the chipset <b>2010</b>, the memory controller <b>2012</b> and the I/O controller <b>2014</b> may be integrated within a single semiconductor circuit.

0047Although certain embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that embodiments in accordance with the present invention may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments in accordance with the present invention be limited only by the claims and the equivalents thereof.