Abstract:
The present patent application comprises a method and apparatus to identify an address of a neighboring node, comprising the steps of identifying an existence of a neighboring cell, receiving a measurement report containing an identifier of the cell; sending an inquiry containing the identifier of the cell to a server, wherein the inquiry inquires what the IP address of the neighboring node of the cell is, and receiving an inquiry response containing the IP address of the neighboring node. In another embodiment, the inquiry containing the identifier of the cell is sent to other nodes.

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119 
     This application claims benefit of U.S. Provisional Application titled “Discovery of Neighbor Cells in E-UTRAN,” filed Jun. 20, 2006 and assigned provisional patent application No. 60/815,290, the entire disclosure of this application being considered part of the disclosure of this application. 
    
    
     BACKGROUND 
     1. Field 
     The present application pertains generally to communications, and more specifically, to discovery of neighbor cells in E-UTRAN. 
     2. Background 
     In the 3 rd  Generation Partnership Project (3GPP) Long Term Evolution (LTE), network nodes have a logical connection to each other over an IP transport. In the decentralized architecture, Node B may be considered to be attached to the network in a “plug-n-play” manner, wherein Node B self-configures operation parameters. It is expected that Node B will use information provided by user equipment (UE). Then the Node B may establish an association with the neighbor cells. However, in the prior art, the UEs do not know the IP addresses of those neighboring cells, the UEs just provide a cell ID. 
     Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile telephone technologies (or 3rd Generation Wireless Mobile Communication Technology). A UMTS network consist of 1) a core network (CN), 2) a UMTS terrestrial radio access network (UTRAN) and 3) user equipment (UE). The core network work provides routing, switching, and transit for user traffic. A Global System for Mobile Communications (GSM) network with General Packet Radio Service (GPRS) is the basic core network architecture that UMTS is based on. The UTRAN provides the air interface access method for User Equipment. A base station is referred as Node B and control equipment for Node Bs is called a radio network controller (RNC). For an air interface, UMTS most commonly uses a wideband spread-spectrum mobile air interface known as wideband code division multiple access (or W-CDMA). W-CDMA uses a direct sequence code division multiple access signaling method (or CDMA) to separate users. 
     A UMTS Terrestrial Radio Access Network (UTRAN) is a collective term for the Node Bs (or base stations) and the control equipment for the Node Bs (or radio network controllers (RNC)) it contains which make up the UMTS radio access network. This is a 3G communications network which can carry both real-time circuit switched and IP based packet switched traffic types. The RNC provides control functionalities for one or more Node Bs. Connectivity is provided between the UE (user equipment) and the core network by the UTRAN. 
     The UTRAN is connected internally or externally to other functional entities by four interfaces: Iu, Uu, Iub and Iur. The UTRAN is attached to a GSM core network via an external interface called Iu. A radio network controller (RNC) supports this interface. In addition, RNC manages a set of base stations called Node Bs through interfaces labeled Iub. The Iur interface connects two RNCs with each other. The UTRAN is largely autonomous from the core network since the RNCs are interconnected by the Iur interface.  FIG. 1  discloses a communication system which uses the RNC, the Node Bs and the Iu and Uu interfaces. The Uu is also external, connects the Node B with the UE, while the Iub is an internal interface connecting the RNC with the Node B. 
     The RNC fills multiple roles. First, it may control the admission of new mobiles or services attempting to use the Node B. Second, from the Node B, i.e. base station, point of view, the RNC is a controlling RNC. Controlling admission ensures that mobiles are allocated radio resources (bandwidth and signal/noise ratio) up to what the network has available. It is where Node B&#39;s Iub interface terminates. From the UE, i.e. mobile, point of view, the RNC acts as a serving RNC in which it terminates the mobile&#39;s link layer communications. From the core network point of view, the serving RNC terminates the Iu for the UE. The serving RNC also controls the admission of new mobiles or services attempting to use the core network over its Iu interface. 
     Cell searching is the procedure by which a UE acquires time and frequency synchronization with a cell and detects the cell ID of that cell. Two signals (“channels”) transmitted in the downlink, the “SCH” (Synchronization Channel) and “BCH” (Broadcast Channel) may be used in a universal terrestrial radio access (or UTRA) cell search. In the UMTS system, UTRA identifies the time division duplex (TDD) and the frequency division duplex (FDD) access mode. The primary purpose of the SCH is to acquire the timing, i.e., at least the SCH symbol timing, and frequency of the received downlink signal. The BCH broadcasts a set of cell and/or system-specific information which may be similar to the current UTRA BCH transport channel. Aside from the SCH symbol timing and frequency information, the UE acquires cell-specific information such as the cell ID. To facilitate cell ID detection, the cell ID may be embedded into the SCH. For example, the cell ID may be directly mapped into the SCH, or different cell ID information may be group-wised. For the case of group ID, cell ID group index can be detected using the SCH, and the cell IDs within the detected cell ID group can be detected using reference symbols or the BCH. As an alternative approach, information regarding the BCH bandwidth and CP length may be detected by blind detection from the SCH or BCH, by using hypothesis testing for example.  FIG. 2  is a flowchart disclosing the basic cell search procedure. 
     SUMMARY OF THE INVENTION 
     In view of the above, the described features of the present invention generally relate to one or more improved systems, methods and/or apparatuses for data communications. In one embodiment, the present patent application comprises a method and apparatus to identify an address of a neighboring node, comprising the steps of identifying an existence of a neighboring cell, receiving a measurement report containing the identifier of the cell; sending an inquiry containing the identifier of the cell to a server, wherein the inquiry inquires what the IP address of the neighboring node of the cell is, receiving an inquiry response containing the IP address of the neighboring node, sending a connection establishment message to the neighboring node, and establishing an association with the neighboring node. 
     In another embodiment, the present patent application comprises a method and apparatus to identify an address of a neighboring node, comprising the steps of identifying an existence of a neighboring cell, receiving a measurement report containing the identifier of the cell, sending an inquiry containing the identifier of the cell to other nodes, wherein the inquiry inquires what the IP address of the neighboring node of the cell is, receiving an inquiry response containing the IP address of the neighboring node, sending a connection establishment message to the neighboring node, and establishing an association with the neighboring node. 
     Further scope of the applicability of the present method and apparatus will become apparent from the following detailed description, claims, and drawings. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, objects, and advantages of the presently disclosed method and apparatus will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein: 
         FIG. 1  is a block diagram of a radio access system having two radio network subsystems along with its interfaces to the core and the user equipment; 
         FIG. 2  is a flowchart disclosing the basic cell search procedure; 
         FIG. 3  is a diagram of a cellular communication system; 
         FIG. 4  is a block diagram of a communication system  100  having a 3GPP LTE/SAE architecture which uses an evolved UTRAN; 
         FIG. 5  is a flow diagram for obtaining an IP address of a target node using an unicast inquiry; 
         FIG. 6  is a flow diagram for obtaining an IP address of a target node using a multicast inquiry; 
         FIG. 7  is a portion of a communication system, including a base station controller and a base station; 
         FIG. 8  illustrates an embodiment of user equipment according to the present patent application; 
         FIG. 9  is a functional block diagram illustrating the steps that are executed when obtaining an IP address of a target node using an unicast inquiry; and 
         FIG. 10  is a functional block diagram illustrating the steps that are executed when obtaining an IP address of a target node using a multicast inquiry. 
     
    
    
     DETAILED DESCRIPTION 
     The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. 
     The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In some instances, well known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present invention. 
     Communication systems may use a single carrier frequency or multiple carrier frequencies. Each link may incorporate a different number of carrier frequencies. Furthermore, an access terminal  10  may be any data device that communicates through a wireless channel or through a wired channel, for example using fiber optic or coaxial cables. An access terminal  10  may be any of a number of types of devices including but not limited to PC card, compact flash, external or internal modem, or wireless or wireline phone. The access terminal  10  is also known as user equipment (UE), a remote station, a mobile station or a subscriber station. Also, the UE  10  may be mobile or stationary. An example of a cellular communication system  100  is shown in  FIG. 3  where reference numerals  102 A to  102 G refer to cells, reference numerals  20 A to  20 G refer to Node Bs or evolved Node Bs (eNode Bs) or base stations and reference numerals  10 A to  10 G refer to UEs. 
       FIG. 4  is a block diagram of a communication system  100  having a 3GPP LTE/SAE architecture which uses an evolved UTRAN (E-UTRAN). User equipment  10  may communicate with one or more eNode Bs  20  by transmitting and receiving data packets through one or more eNodeBs  20 . Unlike the UTRAN discussed above, there is no radio network controller  65  (also referred to as a base station controller (BSC)  65  or modem pool controller (MPC)  65 ). Instead, all radio-related functions are in the eNode Bs  20 . Another difference is found in the core network  44  which is comprised of an IP network operably connected to one or more evolved packet cores (EPC)  49 . As shown in  FIG. 4 , the evolved packet cores  49  may be connected to each other and to individual or many eNode Bs  20 . These multiple connections minimize single points of failure above the eNode Bs  20 . Also, the eNode Bs  20  may be connected to each other. 
     An access network  40  transports data packets between multiple access terminals  10  or user equipment  10 . The access network  40  may be further connected to additional networks outside the access network  40 , such as a corporate intranet or the Internet, and may transport data packets between each user equipment  10  and such outside networks  122 . User equipment  10  that has established an active traffic channel connection with one or more eNode Bs  20  is called active user equipment  10 , and is said to be in a traffic state. User equipment  10  that is in the process of establishing an active traffic channel connection with one or more eNode Bs  20  is said to be in a connection setup state. User equipment  10  may be any data device that communicates through a wireless channel or through a wired channel, for example using fiber optic or coaxial cables. The communication link through which the user equipment  10  sends signals to the eNode B  20  is called a reverse link. The communication link through which an eNodeB  20  sends signals to a user equipment  10  is called a forward link. 
     A goal with current E-UTRAN systems is to minimize operational efforts for E-UTRAN system setup. To deploy LTE quickly and in a cost effective manner, the LTE/SAE system supports automatic installation and setup of newly deployed nodes  20  (eNode Bs) in a plug-and-play manner. Plug and play (PnP) is a computer feature that allows the addition of a new device, such as a peripheral, without reconfiguring the system or manually installing the device drivers. There seem to be two elements in the concept of “plug-and-play” eNode B  20 : 1) Discovery of other nodes and session establishment to discovered nodes  20 ; and 2) Self-configuration of operational parameters by an eNode B  20 . Self-configuration includes the configuration of a neighbor list  45  maintained by an eNode B  20 . The neighbor list  45  may be constructed over time through radio measurements performed by UEs  10  on the E-UTRAN. Self-configuration of the neighbor list  45  in LTE network where the concept of the plug-n-play eNode B  20  is used might be based on a number of methods such as measuring RF on the E-UTRAN, and potentially other supported radio access technologies (RATs), and querying neighbor cell  102  related information via the backbone from the system or via neighbor eNode Bs  20 , etc. 
     To hand over control of user equipment  10  from a source (or serving) eNode B  20  to a target eNode B  20 , the source eNode B  20  uses a connection/association with the target eNode B  20 . A measurement report may be used to assist in the handover. (The term handoff (or handover) involves transferring an ongoing call or data session from one node  20  connected to the core network  44  to another node  20 . The nodes  20  may be in different cells  102 , different sectors of the same cell  102 , or sometimes within the same cell  102 . A handover may occur if user equipment  10  receives a stronger signal (e.g., better metric performance such as signal-to-noise ratio) from another node  20 . Another reason for a handover is if a current node  20  is full.) The UE  10  continuously monitors neighboring cells  102  to determine which may become a candidate cell  102  for handover. The UE  10  then generates a measurement report using a cell ID which identifies a candidate cell  102  for handover and sends the measurement report to the source eNode B  20  which is currently serving the UE  10 . Put another way, the source eNode B  20  is currently serving the cell  102  in which the UE  10  is located. (The cell ID may represent the candidate cell&#39;s  102  geographical location). One problem in the prior art is that the serving (or source) eNode B  20  may not know the Internet Protocol (IP) address of the neighboring or target eNode B  20  of the candidate cell  102  identified in the measurement report. It is desirable for a source eNode B  20  to know the contact point (IP address) of the neighboring or target eNode B  20  of the cell  102  identified by a cell ID reported by the UE  10 . The present patent application addresses this issue. The following is a disclosure of the methods and apparatuses to solve this problem and obtain the IP address of the target eNode B  20 . 
     In the LTE where IP transport is used among the eNode Bs  20  in the core network  44  and the RAN  40 , multicast IP transport and unicast IP transport are available for nodes  20  to communicate with each other. IP multicast is used by a network node  20  to send a message to all the nodes  20  participating in a multicast group IP address. Unicast is used when a network node  20  wants to talk to a particular node  20  for which a unicast IP address is known. 
     Targeted Discovery with Cell ID 
     Unicast Option 
     Both unicast and multicast transmissions may be used to inquire about information of the target eNode B  20  from other nodes  20  or servers  30 . The unicast option can be used when the source eNode B  20  knows a node  20  or server  30  that may have information for the target eNode B  20 . One example is a network  40  where the operator deploys servers/databases  30  that have a mapping database containing cell IDs and IP addresses of eNode Bs  20 . In one example, this mapping database is referred to as a neighbor list  45 . Thus, the source eNodes  20  are capable of evaluating an IP address of a target node  20  from a neighbor list  45  via the E-UTRAN network  40  (neighbor eNode Bs  20 , server  30 , other entity). This is illustrated in  FIG. 5 . In  FIG. 5 , the UE  10  finds a cell ID of a candidate cell  102  that a neighboring eNode B  20  is serving (step  205 ). In step  210 , the measurement report containing the cell ID is sent to the source eNode B  20  (step  210 ). In step  220 , the source eNode B  20  sends a unicast inquiry containing the cell ID to server  30  inquiring what the IP address of the neighboring eNode B  20  is. In step  230 , the server/database  30  sends an inquiry response as a unicast transmission back to the source eNode B  20  containing the IP address of the target (or in this case, neighboring) eNode B  20 . In step  240 , source eNode B  20  sends a connection establishment message to the target or neighboring eNode B  20 . In step  250 , an association is established between the source eNode B  20  and the target or neighboring eNode B  20 . 
     Multicast Option 
     The multicast option may be used when the eNode B  20  would like to collect the information from neighbor nodes  20 . The eNode B  20  sends an inquiry message containing the cell ID of the target cell  102 . Other nodes  20  that received the message respond with required information if they are aware of the eNode B  20  associated with the target cell  102 . Here, the other nodes  20  contain a mapping database for cell IDs and IP addresses of eNode Bs  20 . If a neighboring node  20  knows the cell ID of the UE  10 , the neighboring node  20  may know the IP address of the eNode B  20  serving that cell  102 . The eNode B  20  inquiry contains the cell ID and is multicast to neighboring cells  102 . The response is sent back by a neighboring node  20  which knows the IP address of the UE  10  as a unicast message to the requesting E Node B  20 . 
     Here, rather than configuring the information about each neighboring eNode B in servers/databases  30  that have a mapping database for cell IDs and IP addresses of eNode Bs  20  serving those cells  102 , the radio access network  40  discovery protocols can be used to gather the information from the neighboring transceivers or nodes  20 . Nodes  20  may be configured with sufficient information about neighboring eNode Bs  20  (eg., cell IDs and IP addresses) and the IP addresses are gathered from the neighboring node  20  using discovery protocol(s). 
     This interaction is illustrated in the following call flow shown in  FIG. 6 . The eNode B 2  ( 20 ) (target eNode B) is a neighbor of eNode B 1  ( 20 ) (source eNode B). ENode B 3  ( 20 ) is provisioned with a Neighbor List  45  that includes the IP address of eNode B 2  ( 20 ) and the cell ID of the geographic location (or cell  102 ) served by said eNode B 2  ( 20 ). The ‘Neighbor List Manager’  50  shown in the  FIG. 6  is a logical entity that is responsible for gathering information from neighboring eNode Bs  20 . Thus, the eNode Bs  20  are capable of evaluating an IP address of a serving node  20  from a neighbor list  45  via neighbor eNode Bs  20 .” 
     In  FIG. 6 , the UE  10  finds a cell ID of a candidate cell  102  that a neighboring eNode B  20  is serving (step  305 ). In step  310 , the measurement report containing the cell ID is sent to a source eNode B  20  (step  310 ). In step  320 , the source eNode B  20  sends a multicast inquiry containing the cell ID to surrounding eNode Bs  20  that are radio base stations or on the access gateway (AGW) inquiring what the IP address of the neighboring eNode B  20  is. In step  330 , one of the eNode Bs  20  containing a neighbor list  45  that are radio base stations or on the access gateway (AGW) sends an inquiry response as a unicast transmission back to the source eNode B  20  containing the IP address of the target (or neighboring) eNode B  20 . In step  340 , source eNode B  20  sends a connection establishment message to neighboring eNode B  20 . In step  350 , an association is established between the source eNode B  20  and the target (or neighboring) eNode B  20 . 
       FIG. 7  is detailed herein below, wherein specifically, an eNode B  20  and radio network controller  65  interface with a packet network interface  146 . Radio network controller  65  includes a channel scheduler  132  for implementing a scheduling algorithm for transmissions in system  100 . The channel scheduler  132  determines the length of a service interval during which data is to be transmitted to any particular remote station  10  based upon the remote station&#39;s  10  associated instantaneous rate for receiving data (as indicated in the most recently received DRC signal). The service interval may not be contiguous in time but may occur once every n slots. According to one embodiment, the first portion of a packet is transmitted during a first slot at a first time and the second portion is transmitted 4 slots later at a subsequent time. Also, any subsequent portions of the packet are transmitted in multiple slots having a similar 4 slots spread, i.e., 4 slots apart from each other. According to an embodiment, the instantaneous rate of receiving data Ri determines the service interval length Li associated with a particular data queue. 
     In addition, the channel scheduler  132  selects the particular data queue for transmission. The associated quantity of data to be transmitted is then retrieved from a data queue  172  and provided to the channel element  168  for transmission to the remote station  10  associated with the data queue  172 . As discussed below, the channel scheduler  132  selects the queue for providing the data, which is transmitted in a following service interval using information including the weight associated with each of the queues. The weight associated with the transmitted queue is then updated. 
     Radio network controller  65  interfaces with packet network interface  146 , Public Switched Telephone Network (PSTN)  148 , and all eNode Bs  20  in the communication system  100  (only one eNode B  20  is shown in  FIG. 6  for simplicity). Radio network controller  65  coordinates the communication between remote stations  10  in the communication system and other users connected to packet network interface  146  and PSTN  148 . PSTN  148  interfaces with users through a standard telephone network (not shown in  FIG. 7 ). 
     Radio network controller  65  contains many selector elements  136 , although only one is shown in  FIG. 7  for simplicity. Each selector element  136  is assigned to control communication between one or more base stations  20  and one remote station  10  (not shown). If selector element  136  has not been assigned to a given user equipment  10 , call control processor  141  is informed of the need to page the remote station. Call control processor  141  then directs eNode B  20  to page the remote station  10 . 
     Data source  122  contains a quantity of data, which is to be transmitted to a given remote station  10 . Data source  122  provides the data to packet network interface  146 . Packet network interface  146  receives the data and routes the data to the selector element  136 . Selector element  136  then transmits the data to eNode B  20  in communication with the target remote station  10 . In the exemplary embodiment, each eNode B  20  maintains a data queue  172 , which stores the data to be transmitted to the remote station  10 . 
     The data is transmitted in data packets from data queue  172  to channel element  168 . In one example, on the forward link, a “data packet” refers to a quantity of data which is a maximum of 1024 bits and a quantity of data to be transmitted to a destination remote station within a predetermined “time slot” (such as ≈1.667 msec.). For each data packet, channel element  168  inserts the necessary control fields. In the exemplary embodiment, channel element  168  performs a cyclic redundancy check, CRC, encoding of the data packet and control fields and inserts a set of code tail bits. The data packet, control fields, CRC parity bits, and code tail bits comprise a formatted packet. In the exemplary embodiment, channel element  168  then encodes the formatted packet and interleaves (or reorders) the symbols within the encoded packet. In the exemplary embodiment, the interleaved packet is covered with a Walsh code, and spread with the short PNI and PNQ codes. The spread data is provided to RF unit  170  which quadrature modulates, filters, and amplifies the signal. The forward link signal is transmitted over the air through an antenna to the forward link. 
     At the user equipment  10 , the forward link signal is received by an antenna and routed to a receiver. The receiver filters, amplifies, quadrature demodulates, and quantizes the signal. The digitized signal is provided to a demodulator (DEMOD) where it is despread with the short PNI and PNQ codes and decovered with the Walsh cover. The demodulated data is provided to a decoder which performs the inverse of the signal processing functions done at eNode B  20 , specifically the de-interleaving, decoding, and CRC check functions. The decoded data is provided to a data sink. 
     The DRC signal transmitted by each remote station  10  travels through a reverse link channel and is received at the base station  20  through a receive antenna coupled to RF unit  170 . In one example, the DRC information is demodulated in channel element  168  and provided to a channel scheduler  132  located in the radio network controller  65  or to a channel scheduler  174  located in the eNode B  20 . In a first exemplary embodiment, the channel scheduler  132  is located in the eNode B  20 . In an alternate embodiment, the channel scheduler  132  is located in the radio network controller  65 , and connects to all selector elements  136  within the radio network controller  65 . 
       FIG. 8  illustrates an embodiment of a UE  10  according to the present patent application in which the UE  10  includes transmit circuitry  264  (including PA  308 ), receive circuitry  408 , throttle control  306 , decode process unit  258 , processing unit  302 , multi-carrier control unit  412  and memory  416 . 
     The processing unit  302  controls operation of the UE  10 . The processing unit  302  may also be referred to as a CPU. Memory  416 , which may include both read-only memory (ROM) and random access memory (RAM), provides instructions and data to the processing unit  302 . A portion of the memory  416  may also include non-volatile random access memory (NVRAM). 
     The UE  10 , which may be embodied in a wireless communication device such as a cellular telephone, may also include a housing that contains a transmit circuitry  264  and a receive circuitry  408  to allow transmission and reception of data, such as audio communications, between the UE  10  and a remote location. The transmit circuitry  264  and receive circuitry  408  may be coupled to an antenna  318 . 
     The various components of the UE  10  are coupled together by a bus system  2630  which may include a power bus, a control signal bus, and a status signal bus in addition to a data bus. However, for the sake of clarity, the various busses are illustrated in  FIG. 8  as the bus system  2630 . The AT  106  may also include a processing unit  302  for use in processing signals. Also shown are a power controller  306 , a decode processor  258 , power amplifier  308  and a multi-carrier control unit  412 . 
     The methods and apparatuses of  FIG. 5  described above are performed by corresponding means plus function blocks illustrated in  FIG. 9 . In other words, steps  205 ,  210 ,  220 ,  230 ,  240  and  250  in  FIG. 5  correspond to means plus function blocks  1205 ,  1210 ,  1220 ,  1230 ,  1240  and  1250  in  FIG. 9 . 
     The methods and apparatuses of  FIG. 6  described above are performed by corresponding means plus function blocks illustrated in  FIG. 9 . In other words, steps  305 ,  310 ,  320 ,  330 ,  340 , and  350  in  FIG. 6  correspond to means plus function blocks  1305 ,  1310 ,  1320 ,  1330 ,  1340 , and  1350  in  FIG. 10 . 
     The steps illustrated in  FIGS. 5 ,  6 ,  9  and  10  may be stored as instructions in the form of software or firmware  42  located in memory  416  in the user equipment  10  shown in  FIG. 7 . These instructions may be executed by the processing unit circuit  302  of the user equipment  10  shown in  FIG. 8 . The steps illustrated in  FIGS. 5 ,  6 ,  9  and  10  may also be stored as instructions in the form of software or firmware  43  located in memory  161  in the eNode B  20 . These instructions may be executed by the control unit  162  of the eNode B  20  in  FIG. 7 . 
     Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. 
     The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. 
     The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. 
     In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
     The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. 
     Therefore, the present invention is not to be limited except in accordance with the following claims.