U.S. patent application number 11/538081 was filed with the patent office on 2007-08-09 for access control in radio access network having pico base stations.
Invention is credited to Tomas Nylander, Paul Minkel Teder, Jari Vikberg.
Application Number | 20070183427 11/538081 |
Document ID | / |
Family ID | 37906409 |
Filed Date | 2007-08-09 |
United States Patent
Application |
20070183427 |
Kind Code |
A1 |
Nylander; Tomas ; et
al. |
August 9, 2007 |
ACCESS CONTROL IN RADIO ACCESS NETWORK HAVING PICO BASE
STATIONS
Abstract
Methods and apparatus provide access control to a femto radio
base station (28.sub.f) of a radio access network (24). The radio
access network (24) maintains a database (44) of allowed user
equipment units which are to be permitted access for use of a femto
radio base station (28.sub.f). The database (44) is consulted and
used to determine if a candidate user equipment (30) unit
attempting to use the femto radio base station (28.sub.f) for
access to the radio access network (24) is to be given access. In
some implementations, the candidate user equipment unit (30) is
permitted to use the femto radio base station (28.sub.f) only if
the candidate user equipment unit is an allowed user equipment unit
as determined by the database (44). In some implementations, if the
candidate user equipment unit (30) is not an allowed user equipment
unit as determined by the database (44), the candidate user
equipment unit is redirected to another frequency, or to another
cell, or to another radio access technology network. In some
implementations, if the candidate user equipment unit (30) is not
an allowed user equipment unit as determined by the database (44),
the candidate user equipment unit is required to wait for a
specified wait time before again attempting to use the femto radio
base station (28.sub.f) for access to the radio access network.
Inventors: |
Nylander; Tomas; (Varmdo,
SE) ; Vikberg; Jari; (Jarna, SE) ; Teder; Paul
Minkel; (Taby, SE) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
37906409 |
Appl. No.: |
11/538081 |
Filed: |
October 3, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60722983 |
Oct 4, 2005 |
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60722984 |
Oct 4, 2005 |
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60722982 |
Oct 4, 2005 |
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60723946 |
Oct 6, 2005 |
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60728780 |
Oct 21, 2005 |
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60731495 |
Oct 31, 2005 |
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Current U.S.
Class: |
370/395.2 ;
370/395.52 |
Current CPC
Class: |
H04W 80/00 20130101;
H04W 80/04 20130101; H04W 84/045 20130101; H04W 76/10 20180201;
H04W 88/085 20130101; H04W 48/08 20130101; H04W 24/06 20130101;
H04W 92/12 20130101; H04W 16/24 20130101; H04W 48/16 20130101; H04W
48/02 20130101; H04L 63/101 20130101; H04L 61/1511 20130101; H04W
8/26 20130101; H04W 88/08 20130101; H04L 61/303 20130101; H04W
16/32 20130101; H04W 60/00 20130101; H04W 92/22 20130101; H04W
12/08 20130101; H04W 8/22 20130101; H04W 36/10 20130101; H04W 68/00
20130101; H04W 24/02 20130101 |
Class at
Publication: |
370/395.2 ;
370/395.52 |
International
Class: |
H04L 12/56 20060101
H04L012/56 |
Claims
1. A method of operating a radio access network comprising:
maintaining a database of allowed user equipment units which are to
be permitted access for use of a femto radio base station; using
the database to faciliate a determination if a candidate user
equipment unit attempting to use the femto radio base station for
access to the radio access network is to be given access.
2. The method of claim 1, wherein the candidate user equipment unit
attempting to use the femto radio base station for access to the
radio access network comprises the candidate user equipment unit
attempting to establish a radio connection with the radio access
network through the femto radio base station.
3. The method of claim 1, further comprising permitting the
candidate user equipment unit to use the femto radio base station
only if the candidate user equipment unit is an allowed user
equipment unit as determined by the database.
4. The method of claim 1, further comprising, if the candidate user
equipment unit is not an allowed user equipment unit as determined
by the database, redirecting the candidate user equipment unit to
another frequency, or to another cell, or to another radio access
technology network.
5. The method of claim 1, further comprising, if the candidate user
equipment unit is not an allowed user equipment unit as determined
by the database, requiring the candidate user equipment unit to
wait for a specified wait time before again attempting to use the
femto radio base station for access to the radio access
network.
6. The method of claim 1, further comprising configuring the access
control database with identities of allowed user equipment units
which are to be permitted access for use of the femto radio base
station.
7. The method of claim 1, further comprising sending a status
message to a node of the radio access network for providing
information regarding the determination.
8. A radio access network comprising: a femto radio base station
for serving a femto cell of the radio access network; at least one
radio network controller node, the at least one radio network
controller node configured for controlling a connection between a
user equipment unit and the radio access network using resources of
the femto radio base station; an access control database configured
for facilitating a determination whether a candidate user equipment
unit attempting to use the femto radio base station for access to
the radio access network is to be given access.
9. The apparatus of claim 8, wherein the access control database is
situated as a stand alone node of the radio access network.
10. The apparatus of claim 8, wherein the access control database
is situated at a radio network controller node of the radio access
network.
11. The apparatus of claim 8, wherein the access control database
is configured for facilitating the determination in response to
interrogation by the radio network controller node.
12. A radio access network node comprising an access control
database configured for facilitating a determination whether a
candidate user equipment unit attempting to use a femto radio base
station for access to a radio access network is to be given access
to the radio access network through the femto radio base
station.
13. The apparatus of claim 12, wherein the access control database
is situated as a stand alone node of the radio access network.
14. The apparatus of claim 12, wherein the access control database
is situated at a radio network controller node of the radio access
network.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit and priority of the
following United States provisional patent applications (all of
which are incorporated herein by reference in their entirety):
[0002] U.S. Provisional Patent Application 60/722,983, entitled
"REDIRECTION OF IP-CONNECTED RBS TO THE CORRECT RNC";
[0003] U.S. Provisional Patent Application 60/722,984, entitled
"AUTOMATIC RNC SELECTION FOR IP-CONNECTED RBS";
[0004] U.S. Provisional Patent Application 60/722,982, entitled
FINE-GRAINED ACCESS CONTROL IN A WCDMA SYSTEM USING PICO BASE
STATIONS";
[0005] U.S. Provisional Patent Application 60/723,946, entitled
"PAGING FOR A WCDMA SYSTEM USING PICO BASE STATIONS";
[0006] U.S. Provisional Patent Application 60/728,780, entitled
"AUTOMATIC BUILDING OF NEIGHBOR LISTS IN A MOBILE SYSTEM"; and
[0007] U.S. Provisional Patent Application 60/731,495, entitled
"AUTOMATIC CONFIGURATION OF THE MACRO RADIO IN A PICO BASE
STATION".
[0008] This application is related to the following United States
patent applications (all of which are incorporated herein by
reference in their entirety):
[0009] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1024), filed on even date herewith, entitled "REDIRECTION OF
IP-CONNECTED RADIO BASE STATION TO CORRECT CONTROL NODE";
[0010] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1023), filed on even date herewith, entitled "RADIO NETWORK
CONTROLLER SELECTION FOR IP-CONNECTED RADIO BASE STATION";
[0011] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1022), filed on even date herewith, entitled "ACCESS CONTROL
IN A RADIO ACCESS NETWORK HAVING PICO BASE STATIONS";
[0012] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1021), filed on even date herewith, entitled "PAGING FOR A
RADIO ACCESS NETWORK HAVING PICO BASE STATIONS";
[0013] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1019 filed on even date herewith, entitled "AUTOMATIC BUILDING
OF NEIGHBOR LISTS IN A MOBILE SYSTEM";
[0014] U.S. patent application Ser. No. 11/______ (attorney docket:
2380-1004, filed on even date herewith, entitled "AUTOMATIC
CONFIGURATION OF MACRO RECEIVER OF PICO RADIO BASE STATION";
and,
[0015] U.S. patent application Ser. No. 11/380,824, filed Apr. 28,
2006, entitled "DYNAMIC BUILDING OF MONITORED SET".
I. TECHNICAL FIELD
[0016] This invention pertains to wireless telecommunications, and
particularly to access control in a radio access network having
pico or "femto" radio base stations.
II. RELATED ART AND OTHER CONSIDERATIONS
[0017] In a typical cellular radio system, wireless user equipment
units (UEs) communicate via a radio access network (RAN) to one or
more core networks. The user equipment units (UEs) can be mobile
stations such as mobile telephones ("cellular" telephones) and
laptops with mobile termination, and thus can be, for example,
portable, pocket, hand-held, computer-included, or car-mounted
mobile devices which communicate voice and/or data with radio
access network. Alternatively, the wireless user equipment units
can be fixed wireless devices, e.g., fixed cellular
devices/terminals which are part of a wireless local loop or the
like.
[0018] The radio access network (RAN) covers a geographical area
which is divided into cell areas, with each cell area being served
by a base station. A cell is a geographical area where radio
coverage is provided by the radio base station equipment at a base
station site. Each cell is identified by a unique identity, which
is broadcast in the cell. The base stations communicate over the
air interface with the user equipment units (UE) within range of
the base stations. In the radio access network, several base
stations are typically connected (e.g., by landlines or microwave)
to a radio network controller (RNC). The radio network controller,
also sometimes termed a base station controller (BSC), supervises
and coordinates various activities of the plural base stations
connected thereto. The radio network controllers are typically
connected to one or more core networks. The core network has two
service domains, with an RNC having an interface to both of these
domains.
[0019] One example of a radio access network is the Universal
Mobile Telecommunications (UMTS) Terrestrial Radio Access Network
(UTRAN). The UMTS is a third generation system which in some
respects builds upon the radio access technology known as Global
System for Mobile communications (GSM) developed in Europe. UTRAN
is essentially a radio access network providing wideband code
division multiple access (WCDMA) to user equipment units (UEs). The
Third Generation Partnership Project (3GPP) has undertaken to
evolve further the UTRAN and GSM-based radio access network
technologies.
[0020] As those skilled in the art appreciate, in WCDMA technology
a common frequency band allows simultaneous communication between a
user equipment unit (UE) and plural base stations. Signals
occupying the common frequency band are discriminated at the
receiving station through spread spectrum CDMA waveform properties
based on the use of a high speed, pseudo-noise (PN) code. These
high speed PN codes are used to modulate signals transmitted from
the base stations and the user equipment units (UEs). Transmitter
stations using different PN codes (or a PN code offset in time)
produce signals that can be separately demodulated at a receiving
station. The high speed PN modulation also allows the receiving
station to advantageously generate a received signal from a single
transmitting station by combining several distinct propagation
paths of the transmitted signal. In CDMA, therefore, a user
equipment unit (UE) need not switch frequency when handover of a
connection is made from one cell to another. As a result, a
destination cell can support a connection to a user equipment unit
(UE) at the same time the origination cell continues to service the
connection. Since the user equipment unit (UE) is always
communicating through at least one cell during handover, there is
no disruption to the call. Hence, the term "soft handover." In
contrast to hard handover, soft handover is a "make-before-break"
switching operation.
[0021] Other types of telecommunications systems which encompass
radio access networks include the following: Global System for
Mobile communications (GSM); Advance Mobile Phone Service (AMPS)
system; the Narrowband AMPS system (NAMPS); the Total Access
Communications System (TACS); the Personal Digital Cellular (PDC)
system; the United States Digital Cellular (USDC) system; and the
code division multiple access (CDMA) system described in EIA/TIA
IS-95.
[0022] There are several interfaces of interest in the UTRAN. The
interface between the radio network controllers (RNCs) and the core
network(s) is termed the "Iu" interface. The interface between a
radio network controller (RNC) and its base stations (BSs) is
termed the "Iub" interface. The interface between the user
equipment unit (UE) and the base stations is known as the "air
interface" or the "radio interface" or "Uu interface". In some
instances, a connection involves both a Source and Serving RNC
(SRNC) and a target or drift RNC (DRNC), with the SRNC controlling
the connection but with one or more diversity legs of the
connection being handled by the DRNC. An Inter-RNC transport link
can be utilized for the transport of control and data signals
between Source RNC and a Drift or Target RNC, and can be either a
direct link or a logical link. An interface between radio network
controllers (e.g., between a Serving RNC [SRNC] and a Drift RNC
[DRNC]) is termed the "Iur" interface.
[0023] The radio network controller (RNC) controls the UTRAN. In
fulfilling its control role, the RNC manages resources of the
UTRAN. Such resources managed by the RNC include (among others) the
downlink (DL) power transmitted by the base stations; the uplink
(UL) interference perceived by the base stations; and the hardware
situated at the base stations.
[0024] Those skilled in the art appreciate that, with respect to a
certain RAN-UE connection, an RNC can either have the role of a
serving RNC (SRNC) or the role of a drift RNC (DRNC). If an RNC is
a serving RNC (SRNC), the RNC is in charge of the connection with
the user equipment unit (UE), e.g., it has full control of the
connection within the radio access network (RAN). A serving RNC
(SRNC) is connected to the core network. On the other hand, if an
RNC is a drift RNC (DRNC), it supports the serving RNC (SRNC) by
supplying radio resources (within the cells controlled by the drift
RNC (DRNC)) needed for a connection with the user equipment unit
(UE). A system which includes the drift radio network controller
(DRNC) and the base stations controlled over the Iub Interface by
the drift radio network controller (DRNC) is herein referenced as a
DRNC subsystem or DRNS. An RNC is said to be the Controlling RNC
(CRNC) for the base stations connected to it by an Iub interface.
This CRNC role is not UE specific. The CRNC is, among other things,
responsible for handling radio resource management for the cells in
the base stations connected to it by the Iub interface.
[0025] Some operators are investigating the possibility of
providing home or small area WCDMA coverage for limited number of
users using a small radio base station ("RBS"), also called a
"Femto RBS" and/or a "Home RBS" and/or "pico RBS" and/or "micro
RBS" in some contexts. According to such investigation, the small
RBS would provide normal WCDMA coverage for the end users (e.g., to
a user equipment unit (UE)), and would be connected to the RNC
using some kind of IP based transmission. The coverage area so
provided is called a "femto cell" (to indicate that the coverage
area is relatively small). Other terminology for a femto cell
includes "pico cell" or "micro cell", which is in contrast to a
macro cell covered by a macro or standard radio base station
(RBS).
[0026] One alternative for the IP based transmission is to use
Fixed Broadband access (like xDSL, Cable etc.) to connect the home
RBS to the RNC. Another alternative would be to use Wireless
Broadband access (e.g. HSDPA and Enhanced Uplink; or WiMAX). FIG. 5
illustrates the two different backhaul alternatives in more detail.
The first alternative is labeled "xDSL Backhaul" and the second
alternative is labeled "WiMAX Backhaul".
[0027] In general, ordinary WCDMA base stations (macro RBS) are
able to connect to an RNC using IP-based transmission. Operator
personnel, e.g., employees of an operator company which owns or
maintains the macro RBS nodes and RNC nodes of the radio access
network (RAN), typically install the macro RBS nodes. As part of
the installation, the macro RBS is manually configured with IP
addressing information (DNS name, Fully Qualified Domain Name,
FQDN, or IP-address) of the RNC to which the macro RNC is to
connect.
[0028] By contrast, a femto RBS is typically installed by the end
user rather than the network operator. The end users are also able
to move the Femto RBS geographically from place to place without
the operator being able or willing to control relocation of the
femto RBS. Such user-directed relocation requires that, wherever
the Femto RBS is installed or located, it should connect to the
correct RNC. A "correct RNC" or "preferred RNC" in this sense would
be the same RNC that is controlling the overlaying macro cell of
the radio access network (RAN).
[0029] When the femto RBS is used to enhance local coverage for
example in a small or home office (SOHO) environment, it should be
dedicated to the home or enterprise since the transmission towards
the radio network controller node (and mobile core network) may be
using transmission provided and paid by the home or enterprise
itself. In such case the only terminals belonging to the SOHO or
enterprise should be allowed to access the femto radio base
stations.
[0030] In some situations the end user or SOHO purchases and
possibly operates the femto radio base station. In some instances
the femto radio base station may be a type of base stations that
can only serve a limited number of end users. So it is very
important that the end user or SOHO that has purchased the Femto
RBS have access and not be denied access in view of the femto radio
base station being preoccupied serving with unauthorized users.
[0031] As understood from the two foregoing scenarios of
utilization of a femto radio base station, access control is
important for gaining end-user acceptance for the femto radio base
station concept.
[0032] UE access control for femto radio base stations is sorely
lacking. There are two current mechanisms that have the illusion of
potential access control or are seen as related to access control.
These mechanisms, Access Control Class and Location Update (or
Routing Area Update), are either provided in the UTRAN or between a
mobile station and a Core Network (CN. Each of these mechanisms are
discussed briefly below.
[0033] The radio access network mechanisms are based on the Access
Control Class concept. At subscription, one or more Access Control
Classes are allocated to the subscriber and stored in the USIM of
the subscriber's user equipment unit (UE). These Access Control
Classes can be used to prevent selected classes of users from
sending initial access messages, mostly for load control reasons.
Unfortunately, the Access Control Class concept in UTRAN cannot be
used for fine-grained Access Control. One reason for the deficiency
is related to the fact that only ten different Access Control
Classes are available for normal end-users. With such a limited
number of Access Control Classes, it is impossible to build any
logic for access control for the femto radio base station
concept.
[0034] The mechanisms between the mobile station (e.g., mobile
terminal or user equipment unit (UE)) and the core network are
based on Location Update control. This means that when the mobile
station performs a Location Update towards the core network, the
core network can reject the Location Update based on e.g. the
location of the mobile station. Although the core network can
reject a Location Update, a problem exists in the fact that the
level of rejection can be only done on Location Area (LAI) or PLMN
levels. The core network is not even aware of the Cell Identifier
allocated for each femto radio base station.
[0035] What is needed, therefore, and an object herein provided,
are method, technique, apparatus, and systems for providing
effective access control to a femto radio base station in a radio
access network.
BRIEF SUMMARY
[0036] Methods and apparatus provide access control to a femto
radio base station of a radio access network. The radio access
network maintains a database of allowed user equipment units which
are to be permitted access for use of a femto radio base station.
The database is consulted and used to determine if a candidate user
equipment unit attempting to use the femto radio base station for
access to the radio access network is to be given access.
[0037] In some implementations, the candidate user equipment unit
is permitted to use the femto radio base station only if the
candidate user equipment unit is an allowed user equipment unit as
determined by the database.
[0038] In some implementations, if the candidate user equipment
unit is not an allowed user equipment unit as determined by the
database, the candidate user equipment unit is redirected to
another frequency, or to another cell, or to another radio access
technology network.
[0039] In some implementations, if the candidate user equipment
unit is not an allowed user equipment unit as determined by the
database, the candidate user equipment unit is required to wait for
a specified wait time before again attempting to use the femto
radio base station for access to the radio access network.
[0040] The access control database can be pre-configured and/or
dynamically configured with identities of allowed user equipment
units which are to be permitted access for use of the femto radio
base station
[0041] One example way for the candidate user equipment unit to
attempt to use the femto radio base station for access to the radio
access network is by the candidate user equipment unit attempting
to establish a radio resource control (RRC) connection with the
radio access network through the femto radio base station.
[0042] In one of its aspects, the technology concerns a method of
operating a radio access network. The method includes (1)
maintaining a database of allowed user equipment units which are to
be permitted access for use of a femto radio base station; and (2)
using the database to determine if a candidate user equipment unit
attempting to use the femto radio base station for access to the
radio access network is to be given access.
[0043] Another aspect of the technology concerns a radio access
network comprising at least one femto cell, the femto radio base
station serving a femto cell of the radio access network; at least
one radio network controller node (configured for controlling a
connection between a user equipment unit and the radio access
network using resources of the femto radio base station); and, an
access control database. The access control database is configured
for facilitating a determination whether a candidate user equipment
unit attempting to use the femto radio base station for access to
the radio access network is to be given access. The access control
database can be situated as a stand alone node of the radio access
network or situated at a radio network controller node of the radio
access network. Preferably the access control database is
configured for facilitating the determination in response to
interrogation by the radio network controller node.
[0044] Yet another aspect of the technology concerns a radio access
network node comprising an access control database configured for
facilitating a determination whether a candidate user equipment
unit attempting to use a femto radio base station for access to a
radio access network is to be given access to the radio access
network through the femto radio base station. The access control
database can be situated as a stand alone node of the radio access
network or situated at a radio network controller node of the radio
access network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The foregoing and other objects, features, and advantages of
the invention will be apparent from the following more particular
description of preferred embodiments as illustrated in the
accompanying drawings in which reference characters refer to the
same parts throughout the various views. The drawings are not
necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention.
[0046] FIG. 1A-FIG. 1E are diagrammatic views of an example
embodiment of a telecommunications system including a radio access
network, showing different stages of an access control operation
with respect to a femto radio base station.
[0047] FIG. 2 is a schematic view of an example embodiment of a
femto radio base station.
[0048] FIG. 3 is a schematic view of an example radio network
control (RNC) node.
[0049] FIG. 4 is a diagrammatic view of an example structure of an
access control database for femto radio base stations.
[0050] FIG. 5 is a diagrammatic view showing two different backhaul
alternatives.
[0051] FIG. 6 is a diagrammatic view of an example embodiment of a
status message returned by a radio network controller node after
consultation with a femto access control database.
DETAILED DESCRIPTION
[0052] In the following description, for purposes of explanation
and not limitation, specific details are set forth such as
particular architectures, interfaces, techniques, etc. in order to
provide 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 in other embodiments that depart from
these specific details. That is, those skilled in the art will be
able to devise various arrangements which, although not explicitly
described or shown herein, embody the principles of the invention
and are included within its spirit and scope. In some instances,
detailed descriptions of well-known devices, circuits, and methods
are omitted so as not to obscure the description of the present
invention with unnecessary detail. All statements herein reciting
principles, aspects, and embodiments of the invention, as well as
specific examples thereof, are intended to encompass both
structural and functional equivalents thereof. Additionally, it is
intended that such equivalents include both currently known
equivalents as well as equivalents developed in the future, i.e.,
any elements developed that perform the same function, regardless
of structure.
[0053] Thus, for example, it will be appreciated by those skilled
in the art that block diagrams herein can represent conceptual
views of illustrative circuitry embodying the principles of the
technology. Similarly, it will be appreciated that any flow charts,
state transition diagrams, pseudocode, and the like represent
various processes which may be substantially represented in
computer readable medium and so executed by a computer or
processor, whether or not such computer or processor is explicitly
shown.
[0054] The functions of the various elements including functional
blocks labeled as "processors" or "controllers" may be provided
through the use of dedicated hardware as well as hardware capable
of executing software in association with appropriate software.
When provided by a processor, the functions may be provided by a
single dedicated processor, by a single shared processor, or by a
plurality of individual processors, some of which may be shared or
distributed. Moreover, explicit use of the term "processor" or
"controller" should not be construed to refer exclusively to
hardware capable of executing software, and may include, without
limitation, digital signal processor (DSP) hardware, read only
memory (ROM) for storing software, random access memory (RAM), and
non-volatile storage.
[0055] The present invention is described in the non-limiting,
example context of a telecommunications system 10 shown in FIG. 1A.
The telecommunications system 10 connects to a core network 20. The
telecommunications system 10 comprises a radio access network 24.
The radio access network 24 includes one or more radio network
controller nodes (RNCs) 26 and radio base stations (BS) 28. For
sake of example FIG. 1A particular shows two radio network control
nodes, i.e., a first radio network control 26.sub.1 and a second
radio network control 26.sub.2 as well as one or more macro radio
base stations (only one macro radio base station 28.sub.M being
shown in FIG. 1A) and plural femto radio base stations 28.sub.f1,
28.sub.f2, . . . 28.sub.fx. The macro radio base station 28.sub.M
serves a macrocell C.sub.M. The femto radio base stations
28.sub.f1, 28.sub.f2, . . . 28.sub.fx serve respective femtocells
C.sub.f1, C.sub.f2, . . . C.sub.fx. The person skilled in the art
understands that a radio base station is typically situated at an
interior (e.g., center) of the respective cell which the radio base
station serves, but for sake of clarity the macro radio base
station and femto radio base stations of FIG. 1A are shown instead
as being associated by double headed arrows to their respective
cells. At least some of the femtocells C.sub.f1, C.sub.f2, . . .
C.sub.fx are geographically overlayed or overlapped by the
macrocell CM.
[0056] As used herein, a "femto radio base station" also has the
meaning of a pico radio base station or a micro radio base station,
which serves a femto cell (or pico cell or micro cell). The femto
cell is typically overlaid by one or more macro cells and serves a
smaller geographic area or subscriber constituency than a macro
cell. The technology described herein has particular benefit for a
femto radio base station which can be installed and/or relocated
within a radio access network without the installation or
relocation being controlled by the owner/operator of the radio
access network. In other words, a non-network operator entity (a
femto operator) can acquire the femto radio base station and
situate the femto radio base station in accordance with the
preferences of the femto operator.
[0057] A user equipment unit (UE), such as user equipment unit (UE)
30 shown in FIG. 1A, communicates with one or more cells or one or
more base stations (BS) 28 over a radio or air interface 32. The
user equipment unit can be a mobile station such as a mobile
telephone ("cellular" telephone) and laptop with mobile
termination, and thus can be, for example, portable, pocket,
hand-held, computer-included, or car-mounted mobile device which
communicate voice and/or data with radio access network.
[0058] The radio access network 24 shown in FIG. 1A can be, by way
of non-limiting example, a UMTS Terrestrial Radio Access Network
(UTRAN). In the UTRAN, radio access is preferably based upon
Wideband Code Division Multiple Access (WCDMA) with individual
radio channels allocated using CDMA spreading codes. Of course,
other access methods may be employed. The nodes 26 and 28 are
respectively termed the radio network control node and the radio
base station nodes in view of the UTRAN example. However, it should
be understood that the term radio network control and radio base
station also encompasses nodes having similar functionality for
other types of radio access networks. Other types of
telecommunications systems which encompass other types of radio
access networks include the following: Global System for Mobile
communications (GSM); Advance Mobile Phone Service (AMPS) system;
the Narrowband AMPS system (NAMPS); the Total Access Communications
System (TACS); the Personal Digital Cellular (PDC) system; the
United States Digital Cellular (USDC) system; and the code division
multiple access (CDMA) system described in EIA/TIA IS-95.
[0059] The radio access network 24 is connected to core network 20
over an interface, such as the Iu interface for UTRAN. The core
network 20 of FIG. 1A can comprise, among other things a Mobile
Switching Center (MSC) node, a Gateway MSC node (GMSC), a Gateway
General Packet Radio Service (GPRS) support node (GGSN), and a
Serving GPRS Support node (SGSN). Circuit switched (CS) network or
packet switched (PS) network can be connected to core network
20.
[0060] For sake of simplicity, the radio access network 24 of FIG.
1A is shown with only two RNC nodes 26. Multiple radio network
controller nodes (RNCs) may be provided, with each RNC 26 being
connected to one or more base stations (BS) 28. It will be
appreciated that a different number of base stations than that
shown in FIG. 1A can be served by a radio network control 26, and
that RNCs need not serve the same number of base stations.
Moreover, an RNC can be connected over an Iur interface to one or
more other RNCs in radio access network 24. The radio network
controller node (RNC) 26 communicates over an interface Iub with
the macro radio base station 28.sub.M. Further, those skilled in
the art will also appreciate that a base station such as the macro
radio base station 28 is sometimes also referred to in the art as a
radio base station, a node B, or B-node. Each of the radio
interface 32, the Iu interface, the Iur interface, and the Iub
interface are shown by dash-dotted lines in FIG. 1A.
[0061] FIG. 1A also shows by dash-dotted lines a Iub interface
which exists between the femto radio base stations 28.sub.f and the
RNC node 26. The Iub interface is preferably formed by an internet
protocol (IP) connection.
[0062] FIG. 1A also shows that the radio network controller nodes
(RNCs) of radio access network 24 have access to access control
database 44. The femto access control database 44 may be provided
as a separate node of radio access network 24 as shown, or may be
an adjunct of another RAN node (e.g., included in one or more radio
network controller nodes (RNCs) 26). Alternatively, in certain
cases, access to femto access control database 44 can even be
provided through core network 20. In the particular radio access
network 24 shown in FIG. 1A, Femto access control database 44 is
shown as being connected to radio network control nodes, and
particularly to first radio network controller node RNC 26.sub.1
and second radio network controller node RNC 26.sub.2.
[0063] As shown by an example format depicted in FIG. 4, femto
access control database 44 maintains or lists allowed user
equipment units which are to be permitted access for use of a femto
radio base station. As shown in FIG. 4, femto access control
database 44 is formatted to list, for each of L number of femto
radio base stations, identifications of the user equipment units
which have allowed access status to the respective femto radio base
station. An example such identification for a user equipment unit
(UE) may be the International Mobile Subscriber Identity (IMSI) of
the user equipment units. As explained hereinafter, femto access
control database 44 is consulted and used to determine if a
candidate user equipment unit attempting to use the femto radio
base station for access to the radio access network is to be given
access.
[0064] FIG. 1A can be viewed as illustrating generic access of
femto radio base station 28.sub.fj to the radio access network
(RAN), e.g., to its radio network controller node (e.g., radio
network controller node 26.sub.1 in the specifically illustrated
scenario). By "generic access" is meant that the access afforded to
femto radio base station 28.sub.fj can be either broadband fixed
access or broadband wireless (mobile) access (e.g., WiMAX) as
described above. In broadband wireless (mobile) access, access for
femto radio base station 28.sub.fj to the radio access network 24
is through a macro radio base station, and can occur using, e.g.
High Speed Downlink Packet Access (HSDPA) and Enhanced Uplink; or
WiMAX. To cater generically to the access types, in FIG. 1A the
femto radio base stations 28.sub.f including femto radio base
stations 28.sub.fj are connected to a communications network 38. An
example of such communications network is an IP network 38. Unless
otherwise specifically exempted in its context, aspects of the
technology described herein are applicable to all types of access,
including broadband fixed access and broadband mobile access (e.g.,
broadband wireless access).
[0065] FIG. 2 illustrates basic, selected, representative
constituent elements of an example generic femto radio base station
28.sub.f. One or more of the femto radio base stations 28.sub.f1,
28.sub.f2, . . . 28.sub.fx can take the form of the generic femto
radio base station 28.sub.f shown of FIG. 2. The femto radio base
station 28.sub.f of FIG. 2 is shown as including, among its other
unillustrated constituent units, an interface unit 50 for
connecting with radio network control node 26 over the Iub
interface; one or more radio frequency transceivers 52; an optional
UTRAN receiver 54; and, a data processing system, section, or unit
56.
[0066] The IP interface unit 50 is a normal Iub interface unit, but
has connectivity to an IP network Thus, as explained hereinafter,
connection between RNC 26 and the femto radio base stations
28.sub.f preferably utilizes, e.g., Internet Protocol (IP)-based
transmission.
[0067] The radio frequency transceivers 52 are for communicating
over the radio or air interface with user equipment units (UEs) in
the femtocell served by the femto radio base station 28.sub.f. The
number of radio frequency transceivers 52 depends on various
factors including capacity of the femto radio base station to
handle mobile connections.
[0068] Some femto radio base station nodes may further also
comprise receiver 54 for receiving scanned cell information
broadcast for one or more receivable cells of the radio access
network. For example, in one example implementation the femto radio
base station 28.sub.f comprises or is equipped with a WCDMA
receiver (a UE) as its radio frequency receiver 54, thereby
enabling the femto radio base station to camp on signals from
receivable cells (including both WCDMA macrocells and femtocells)
and to read the relevant system or network information broadcast in
those cells.
[0069] FIG. 3 illustrates basic, selected, representative
constituent elements of an example radio network control node 26.
The radio network control node 26 can comprise several interface
units, such as an interface unit 70 for connecting radio network
control node 26 over the Iu interface to core network 20; an
interface unit 72 for connecting radio network control node 26 over
the Iur interface to other (unillustrated) radio network
controllers; one or more interface units 74 for connecting radio
network control node 26 over the Iub interface to respective one or
more macro radio base station 28.sub.M; and, one or more interface
units 76 for connecting radio network control node 26 over the Iub
interface to respective one or more femto radio base stations
28.sub.f1, 28.sub.f2, . . . 28.sub.fx. The connection between RNC
26 and the femto radio base stations 28.sub.m preferably utilizes,
e.g., Internet Protocol (IP)-based transmission. The connection
between RNC 26 and the macro radio base station(s) 28.sub.M can
utilize, e.g., Internet Protocol (IP)-based and/or ATM-based
transmission.
[0070] In addition to interface units, the radio network control
node 26 comprises numerous unillustrated constituent units, as well
as a data processing system, section, or unit 80. As shown in FIG.
3, in an example, non-limiting implementation the data processing
system 80 of radio network control node 26 comprises a control
section (e.g., controller 82); a handover unit 84; a combiner and
splitter unit 86 (involved, e.g., in handling diversity legs of a
connection); and, a femto radio base station handler 88. The femto
radio base station handler 88 includes a searcher interface 92 for
femto access control database 44.
[0071] At the time shown in FIG. 1A, user equipment unit (UE) 30 is
seeking access to radio access network 24 via femto radio base
station 28.sub.fj. The femto radio base station 28.sub.fj has been
activated by a femto operator and has been connected to a correct
radio network controller node (e.g., radio network controller
26.sub.2). The femto radio base station 28.sub.fj can become
connected to is correct radio network controller node in various
ways, such as those explained, e.g., in U.S. patent application
Ser. No. 11/______ (attorney docket: 2380-1022), filed on even date
herewith, entitled "REDIRECTION OF IP-CONNECTED RBS TO THE CORRECT
RNC"; and U.S. patent application Ser. No. 11/______ (attorney
docket: 2380-1023), filed on even date herewith, entitled
"AUTOMATIC RNC SELECTION FOR IP-CONNECTED RBS", both of which are
incorporated herein by reference.
[0072] As explained previously, there may be economic exclusivities
for femto radio base station 28.sub.fj. That is, the owner/operator
of femto radio base station 28.sub.fj is jealous regarding which
and/or how many user equipment units utilize femto radio base
station 28.sub.fj for access to radio access network 24. Such
jealously may arise, for example, by the fact that the
owner/operator of femto radio base station 28.sub.fj is obligated
to pay for the connections via femto radio base station 28.sub.fj
to the radio access network 24, or the fact that the owner/operator
wants to ensure that the user equipment units associated with the
owner/operator's community, enterprise, SOHO, or business or the
like is guaranteed access to radio access network 24 via femto
radio base station 28.sub.fj with priority or exclusivity over
other user equipment units which are not members of the
owner/operators's community, etc.
[0073] FIG. 1A shows, as event or step S-1A, the user equipment
unit (UE) 30 (also known herein as a "candidate" user equipment
unit) attempting to use femto radio base station 28.sub.fj for
access to radio access network 24. One example way for the
candidate user equipment unit 30 to attempt to use femto radio base
station 28.sub.fj for access to radio access network 24 is by
candidate user equipment unit 30 attempting to establish a radio
resource control (RRC) connection (RRC connection establishment)
with radio access network 24 through femto radio base station
28.sub.fj. Thus, as event or step S-1A, candidate user equipment
unit 30 sends a RRC connection establishment message to radio
network controller node 26.sub.2 via femto radio base station
28.sub.fj. The RRC connection establishment message of step S-1A
includes identification information regarding the candidate user
equipment unit 30, e.g., the IMSI of candidate user equipment unit
30. The femto radio base station 28.sub.fj relays the RRC
connection establishment message of step S-1A over the Iub
interface to radio network controller 26.sub.2.
[0074] Upon reception of the RRC connection establishment message
of step S-1A, the request for access inherent in the RRC connection
establishment message of step S-1A is processed by radio network
controller node 26.sub.2, and particularly by femto radio base
station handler 88. The femto radio base station handler 88 directs
searcher interface 92 to prepare a query of femto access control
database 44 so that radio network controller node 26.sub.2 can
ascertain whether candidate user equipment unit 30 is permitted
access to radio access network 24 via femto radio base station
28.sub.fj. To this end, FIG. 1B shows radio network controller node
26.sub.2 sending a query to femto access control database 44 to
find out whether the candidate user equipment unit 30 is a
permitted user/subscriber/customer of femto radio base station
28.sub.fj. The query to femto access control database 44 includes
both the identifier of the candidate user equipment unit 30 and an
identifier of the femto radio base station 28.sub.fj for which
permission is sought.
[0075] FIG. 1C depicts, as step or event S-1C, the femto access
control database 44 receiving the query from radio network
controller node 26.sub.2 and performing a search to determine if
the identifier (IMSI) of the candidate user equipment unit 30 is
listed as an allowed identifier for the particular femto radio base
station identified in the query message, i.e., femto radio base
station 28.sub.fj. As shown in FIG. 4, in one example configuration
of femto access control database 44, for each femto radio base
station encompassed by femto access control database 44 there is a
list of permitted or allowed user equipment units, the list
preferably being formatted in terms of user equipment unit
identifier such as IMSI, for example.
[0076] FIG. 1D also depicts femto access control database 44
returning a response radio network controller node 26.sub.2 after
femto access control database 44 has conducted its search. In its
most simple implementation, the response message (depicted as step
or event S-1D in FIG. 1D) advises merely whether candidate user
equipment unit 30 is allowed or not to use femto radio base station
28.sub.fj for RAN access.
[0077] Thus, when candidate user equipment unit 30 establishes a
RRC connection via femto radio base station 28.sub.fj, the radio
network controller node (radio network controller node 26.sub.2 in
the illustrated scenario) checks femto access control database 44
to determine whether an allowed IMSI for this femto radio base
station 28.sub.fj is attempting to establish the connection. If the
femto access control database 44 indicates in step S-1D that
candidate user equipment unit 30 is allowed to access radio access
network 24 using femto radio base station 28.sub.fj, the RRC
connection establishment is approved by the radio network
controller node (e.g., radio network controller node 26.sub.2).
FIG. 1E depicts, as step or event S-1E, the radio network
controller node 26.sub.2 sending a status message to candidate user
equipment unit 30. In the case that candidate user equipment unit
30 is a permitted or allowed user equipment unit for femto radio
base station 28.sub.fj, the status message takes the form of an
approval message. In the case that candidate user equipment unit 30
is not a permitted or allowed user equipment unit for femto radio
base station 28.sub.fj, the status message takes the form of a
denial message.
[0078] In its simplest form, the denial message of step S-1E can
include a curt notification that the candidate user equipment unit
30 is denied use of femto radio base station 28.sub.fj. In other
forms, the denial message of step S-1E can include information
whereby the candidate user equipment unit is redirected to another
frequency, or to another cell, or to another radio access
technology network. In yet another form, the denial message of step
S-1E can require candidate user equipment unit 30 to wait for a
specified wait time before again attempting to use femto radio base
station 28.sub.fj for access to radio access network 24.
[0079] Thus, if candidate user equipment unit 30 is not allowed to
access radio access network 24 using femto radio base station
28.sub.fj, the RNC (e.g., radio network controller node 26.sub.2)
rejects the RRC connection establishment. The RNC can indicate
different actions for the mobile station in the event of a denial.
These are all based on existing mechanisms in the RRC protocol.
[0080] As shown in FIG. 6, an example status message 100 may
include several fields of information elements (IEs) which
indicates the different action to be taken by candidate user
equipment unit 30 in view of the denial. Foremost among the fields
or information elements (IE) is information element (IE) 102 which
specifies whether the candidate user equipment unit 30 is allowed
or denied. Such fields or information element(s) (IEs) may include
one or more of the following: a "Rejection Cause IE" 104; a "Wait
IE" 106, and/or a "Redirection IE" 108, for example. Thus, as
indicated above, in its denial message the RNC may: [0081] Indicate
congestion as the Rejection Cause IE 104 and/or wait time IE 106
until candidate user equipment unit 30 is again allowed to access
the cell of the femto radio base station 28.sub.fj. The wait time
can be also set to `infinite` meaning that candidate user equipment
unit 30 is not allowed to retry establishment of the RRC connection
via femto radio base station 28.sub.fj for this transaction. [0082]
Indicate another frequency in the Redirection Info IE 108. In such
case, candidate user equipment unit 30 should find a suitable cell
on the indicated frequency and camp on such indicated cell. This
indicated frequency would preferably be a frequency used for the
macro WCDMA coverage. [0083] Indicate Inter-Radio Access Technology
(Inter-RAT) cell information in the Redirection Info IE 108. In
such case, the candidate user equipment unit 30 should find a
suitable cell of another radio access technology (e.g., a GSM cell
of a GSM radio access network if current radio access technology is
UTRAN), and camp on the alternate RAT cell.
[0084] The information to include in the information element(s)
such as "Rejection Cause IE" 104, "Wait IE" 106, and "Redirection
IE" 108 may be gleaned from other databases or resources access
from or maintained the radio network controller node itself, or
alternatively by radio access network or, in some cases, the core
network. In the event that the candidate user equipment unit 30 is
not approved but nevertheless instructed to "wait", it is expected
that, at least in some instances, the owner/operator of femto radio
base station 28.sub.fj has some input or discretion in determining
whether a guest candidate user equipment unit will be permitted
subsequently to use femto radio base station 28.sub.fj should
congestion eventually dissipate or decrease. To this end, femto
access control database 44 may include an additional optional field
of information to give guest privileges to an otherwise non-allowed
candidate user equipment unit 30 when traffic conditions so permit.
In other words, a user equipment unit which is configured in the
femto access control database 44 as a guest may be allowed optional
access to femto cell C.sub.fj, but only when traffic conditions so
permit (e.g., low congestion).
[0085] Information such as the information included in the status
message of step S-1E and FIG. 6 can additionally and optionally be
provided to the femto radio base station 28.sub.fj, or any other
network node (macro or pico) having a need or desire or advantage
for knowing the outcome of the access request. Such information to
other nodes may be beneficial, for example, in architectures in
which the other node (e.g., a radio base station node) currently
has, or may in the future have, capabilities of handling access
control, either totally or partially.
[0086] The femto access control database 44 can be pre-configured
and/or dynamically configured with identities of allowed user
equipment units which are to be permitted access for use of the
femto radio base station. In this regard, the femto radio base
station 28.sub.fj is identified in the RNC and in femto access
control database 44 with an identifier such as (for example) a
serial number or the like. The association between serial number
and mobile subscriber identity (e.g., IMSI) is initially done, e.g.
at a store or other release point at which the pico-base station is
purchased or acquired by the pico/femto owner/operator.
Furthermore, it is also possible for the femto/pico owner/operator
of femto radio base station 28.sub.fj to define which mobile
subscribers (e.g., which user equipment units (UEs) are able to
access femto radio base station 28.sub.fj. Such control of access
(be it either remote, subsequent, and/or dynamic) can be achieved,
e.g., using a web-based service, where the owner of the base
station is first authorized and is then able to define the allowed
or permitted mobile subscribes. The mobile subscribers are
preferably identified using MSISDN number and then the service can
map these values to the IMSI values of the user equipment units for
use by the femto access control database 44.
[0087] Thus, the technology enables a femto RBS to be genuinely
dedicated to a set of users. Such dedication and exclusivity is
especially important if, for example, the end users' own broadband
connection is used for transmission between base station and RNC or
if the end user has paid for a certain WCDMA air capacity in the
femto RBS.
[0088] Thus, as one aspect of the technology, an access control
database is configured for facilitating (e.g., making or assisting
in the making of) a determination whether a candidate user
equipment unit attempting to use a femto radio base station for
access to a radio access network is to be given access to the radio
access network through the femto radio base station. The access
control database can be situated as a stand alone node of the radio
access network or situated at a radio network controller node of
the radio access network.
[0089] The foregoing principle/method can also be applied for radio
technologies other than WCDMA, which is illustrated only as an
example. Other suitable technologies include but are not limited to
GSM, CDMA, WiMAX etc. The technology has particular relevance of
the aforementioned and conveniently described system and scenarios,
but could also be applied in other cases and for other
networks.
[0090] Although various embodiments have been shown and described
in detail, the claims are not limited to any particular embodiment
or example. None of the above description should be read as
implying that any particular element, step, range, or function is
essential. The invention is not to be limited to the disclosed
embodiment, but on the contrary, is intended to cover various
modifications and equivalent arrangements.
* * * * *