Network-assisted cell access

Abstract

Providing for access point assisted signal acquisition for heterogeneous access point wireless networks is described herein. By way of example, a closed subscriber group (CSG) base station, such as a home NodeB (HNB) can be configured to provide temporary, limited access to a UE that is not authorized to access the HNB. Upon receiving and rejecting an access probe, the HNB can negotiate with a surrounding macro network to provide service for the UE. Further, the HNB can forward signal acquisition data, to assist in proper decoding of pilot or synchronization signals of the macro network. In particular aspects, the HNB can reduce power or blank transmissions on reserved access resources to reduce interference for the UE. By these and other disclosed mechanisms, the HNB can assist a non-CSG subscriber to obtain network service, and mitigate interference effects due to proximity to the UE.

What is claimed is: 
     
         1 . A method of network-assisted wireless access, comprising:
 receiving a network access probe;   accessing a closed subscriber group (a CSG) and identifying the network access probe as originating from a member or a non-member of the CSG; and   providing temporary access assistance in response to the network access probe if the network access probe originates from the non-member of the CSG.   
     
     
         2 . The method of  claim 1 , wherein providing temporary access assistance further comprises relaying a cell ID or a relative timing of a neighboring general access BS in response to the network access probe. 
     
     
         3 . The method of  claim 1 , wherein providing temporary access assistance further comprises obtaining relative signal strength measurements of neighboring BSs from a requesting AT and submitting the relative signal strength measurements to a wireless network associated with the requesting AT. 
     
     
         4 . The method of  claim 1 , wherein providing temporary access assistance further comprises obtaining an access refusal for the network access probe from a neighboring general access BS or a service provider of a requesting AT, and forwarding the access refusal to the requesting AT. 
     
     
         5 . The method of  claim 1 , wherein providing temporary access assistance further comprises obtaining an ID and a relative timing of a candidate serving BS selected by a wireless network for providing wireless service for a requesting AT, and forwarding the ID or the relative timing to the requesting AT. 
     
     
         6 . The method of  claim 5 , wherein providing temporary access assistance further comprises negotiating a set of resources to be at least in part reserved for communication between a serving BS and the requesting AT. 
     
     
         7 . The method of  claim 6 , further comprising reducing power or blanking transmission on the set of resources. 
     
     
         8 . The method of  claim 5 , further comprising obtaining a reserved RACH sequence for a BS selected to serve the requesting AT (a serving BS) and forwarding the reserved RACH sequence to the requesting AT to facilitate access to the wireless network via the serving BS. 
     
     
         9 . The method of  claim 8 , further comprising forwarding at least one of the following to the requesting AT to facilitate access to the serving BS:
 a cell ID or a relative timing of the serving BS; or   a set of resources established for a reserved RACH and system information pertaining to the reserved RACH.   
     
     
         10 . The method of  claim 9 , further comprising terminating direct wireless communication with the requesting AT. 
     
     
         11 . An apparatus for wireless communication, comprising:
 a wireless communication interface that receives and decodes a network access probe;   memory for storing modules configured to provide limited network access for assisted acquisition; and   a data processor for executing the modules, which comprise:
 a reference module that accesses a closed subscriber group (a CSG) and identifies the network access probe as originating from a member or a non-member of the CSG; and 
 a limited access module that provides limited service for network access in response to the network access probe if the reference module identifies the network access probe as originating from the non-member of the CSG. 
   
     
     
         12 . The apparatus of  claim 11 , wherein the limited access module relays cell ID or relative timing of a neighboring general access BS in response to the network access probe. 
     
     
         13 . The apparatus of  claim 11 , wherein:
 the limited access module decodes a relative signal strength measurement of neighboring BSs received from a requesting AT; and   the apparatus further comprises a network interface that submits the relative signal strength measurement to a service provider network associated with the AT.   
     
     
         14 . The apparatus of  claim 11 , wherein the limited access module obtains an access refusal for the network access probe from a neighboring general access BS or a service provider of a requesting AT, and forwards the access refusal to the requesting AT. 
     
     
         15 . The apparatus of  claim 11 , wherein the limited access module obtains an ID and relative timing data of a serving BS for a requesting AT, and forwards the ID or the relative timing data to the requesting AT. 
     
     
         16 . The apparatus of  claim 15 , further comprising a resource protocol module that negotiates wireless resources for communication between the serving BS and requesting AT. 
     
     
         17 . The apparatus of  claim 15 , wherein the limited access module obtains a reserved RACH sequence for the serving BS and forwards the reserved RACH sequence to the requesting AT to facilitate a limited access to the serving BS. 
     
     
         18 . An apparatus for network-assisted wireless access, comprising:
 means for receiving a network access probe transmitted on a wireless uplink;   means for accessing a closed subscriber group (a CSG) and determining whether a device transmitting the network access probe is a member or a non-member of the CSG; and   means for providing limited service for network access in response to the network access probe if the device is the non-member of the CSG.   
     
     
         19 . At least one processor configured for network-assisted wireless access, comprising:
 a first module for receiving a network access probe on a wireless uplink;   a second module for accessing a closed subscriber group (a CSG) and determining whether a device transmitting the network access probe is a member or a non-member of the CSG; and   a third module for providing limited service for network access in response to the network access probe if the device is the non-member of the CSG.   
     
     
         20 . A computer program product, comprising:
 a computer-readable medium, comprising:   a first set of codes for causing a computer to receive a network access probe on a wireless uplink;   a second set of codes for causing the computer to access a closed subscriber group (a CSG) and identify whether a device transmitting the network access probe is a member or a non-member of the CSG; and   a third set of codes for causing the computer to provide limited service for network access in response to the network access probe if the device is the non-member of the CSG.   
     
     
         21 . A method of network-assisted access, comprising:
 obtaining a network access request that is relayed from a neighboring closed subscriber group base station (CSG BS);   identifying a serving BS for the network access request; and   forwarding a cell ID and timing information of the serving BS via the neighboring CSG BS to a requesting AT, if the requesting AT is authorized for network access.   
     
     
         22 . The method of  claim 21 , further comprising negotiating reserved resources for communication between the requesting AT and the serving BS. 
     
     
         23 . The method of  claim 22 , further comprising receiving an access probe from the requesting AT over the reserved resources according to a modified access protocol. 
     
     
         24 . The method of  claim 23 , further comprising relaying an advanced timing command to the requesting AT in response to the access probe. 
     
     
         25 . The method of  claim 22 , wherein the negotiating reserved resources further comprises determining a reserved RACH sequence allocated to the requesting AT. 
     
     
         26 . The method of  claim 25 , wherein the reserved RACH sequence is generated from a root sequence reserved for the requesting AT or reserved for the serving BS. 
     
     
         27 . The method of  claim 25 , further comprising monitoring a reserved RACH and obtaining an access probe containing the reserved RACH sequence, wherein the access probe is in accordance with a modified access protocol. 
     
     
         28 . The method of  claim 25 , further comprising responding to the reserved RACH sequence with a RACH acknowledgment and an advanced timing command if the requesting AT is authorized to access the serving BS. 
     
     
         29 . The method of  claim 21 , further comprising employing a predetermined set of resources, reserved for interference mitigation by the neighboring CSG BS, for communication between the requesting AT and the serving BS. 
     
     
         30 . An apparatus for facilitating network-assisted wireless access, comprising:
 a communication interface that obtains a network access probe that is relayed to the apparatus from a neighboring closed subscriber group base station (a neighboring CSG BS);   a memory that stores instructions configured to employ the neighboring CSG BS for access assistance; and   a data processor that executes modules to implement the instructions, the modules comprising:
 an admission control module to determine whether a BS associated with the apparatus is to be a serving BS for an access terminal (AT) transmitting the network access probe; 
 an interface module that forwards a cell ID and timing information of the BS via the neighboring CSG BS to the AT if the admission control module determines that the AT is authorized for network access. 
   
     
     
         31 . The apparatus of  claim 30 , further comprising a resource protocol module that negotiates reserved resources for communication between the AT and the BS. 
     
     
         32 . The apparatus of  claim 31 , further comprising an access module that monitors the reserved resources for a modified protocol access probe from the AT. 
     
     
         33 . The apparatus of  claim 32 , wherein the access module decodes the modified protocol access probe over the reserved resources. 
     
     
         34 . The apparatus of  claim 33 , wherein the access module relays an advanced timing command to the AT in response to the modified protocol access probe. 
     
     
         35 . The apparatus of  claim 31 , wherein the resource protocol module allocates a reserved RACH sequence to the AT. 
     
     
         36 . The apparatus of  claim 35 , wherein the reserved RACH sequence is generated from a root sequence reserved for the AT or reserved for the BS. 
     
     
         37 . The apparatus of  claim 35 , wherein an access module monitors a reserved RACH and decodes a modified protocol access probe containing the reserved RACH sequence. 
     
     
         38 . The apparatus of  claim 37 , wherein the access module responds to the reserved RACH sequence with a RACH acknowledgment and timing advanced command if the requesting AT is authorized to access the serving BS. 
     
     
         39 . The apparatus of  claim 30 , further comprising a resource configuration module that employs a predetermined set of resources, reserved for the BS by the neighboring CSG BS, for communication with the AT. 
     
     
         40 . An apparatus that facilitates network-assisted wireless access, comprising:
 means for obtaining a network access request that is relayed from a neighboring closed subscriber group base station (a neighboring CSG BS);   means for identifying a serving BS for a device transmitting the network access request; and   means for forwarding a cell ID and timing information of the serving BS via the neighboring CSG BS to a requesting AT if the requesting AT is authorized for network access.   
     
     
         41 . At least one processor configured for facilitating network-assisted wireless access, comprising:
 a first module that obtains a network access request that is relayed from a neighboring closed subscriber group base station (a neighboring CSG BS);   a second module that identifies a serving BS for a device transmitting the network access request; and   a third module that forwards a cell ID and timing information of the serving BS via the neighboring CSG BS to a requesting AT if the requesting AT as authorized for network access.   
     
     
         42 . A computer program product, comprising:
 a computer-readable medium, comprising:   a first set of codes for causing a computer to obtain a network access request that is relayed from a neighboring closed subscriber group base station (a neighboring CSG BS);   a second set of codes for causing the computer to identify a serving BS for a device transmitting the network access request; and   a third set of codes for causing the computer to forward a cell ID and timing information of the serving BS via the neighboring CSG BS to a requesting AT if the requesting AT is authorized for network access.