Telecommunications – Transmitter and receiver at separate stations – Having measuring – testing – or monitoring of system or part
Reexamination Certificate
2000-02-22
2004-09-21
Tran, Pablo N. (Department: 2685)
Telecommunications
Transmitter and receiver at separate stations
Having measuring, testing, or monitoring of system or part
C455S456500, C455S067700, C370S331000
Reexamination Certificate
active
06795689
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to cellular radio communications, and more particularly, to the reporting and handling of cell status messages from a radio base station. The invention finds one example application in Wideband Code Division Multiple Access (WCDMA) communications systems.
BACKGROUND AND SUMMARY OF THE INVENTION
Direct Sequence Code Division Multiple Access (DS-CDMA) allows signals to overlap in time and frequency so that CDMA signals from multiple users simultaneously operate in the same frequency band or spectrum. In principle, a source information digital data stream to be transmitted is impressed upon a much higher rate data-stream generated by a pseudo-random noise (PN) code generator. This combination of a higher bit rate code signal with a lower bit rate information stream “spreads” the bandwidth of the information data stream. Each information data stream is allocated a unique PN or spreading code (or a PN code having a unique offset in time) to produce a signal that can be separately received at a receiving station. From a received composite signal of multiple, differently-coded signals, a PN coded information signal is isolated and demodulated by correlating the composite signal with a specific PN spreading code associated with that PN coded information signal. This inverse, de-spreading operation “compresses” the received signal to permit recovery of the original data and at the same time suppress interference from other users.
Wideband CDMA systems contain one or several radio frequency carriers. Each radio frequency carrier contains a number of spreading codes which may be allocated to provide different data rates to satisfy different mobile user requirements. Some of those spreading codes are used for traffic channels and some are used for common control channels such as random access channels, paging channels, broadcast channels, etc. In order to provide flexibility in how bandwidth and other radio resources are allocated in wideband CDMA systems, a “logical” cell is defined. Such a logical cell may be allocated more than one radio frequency carrier thereby permitting resources associated with different carriers belonging to the same cell to be allocated, for example, to a single mobile station requiring a high bit rate connection. The additional carrier(s) effectively provide more traffic channels.
One example of a wideband CDMA system is the universal mobile telecommunications system (UMTS)
10
shown in
FIG. 1. A
representative, circuit-switched, external core network, shown as a cloud
12
may be for example the public switched telephone network (PSTN) and/or the integrated services digital network (ISDN). Another circuit-switched, external core network may correspond to another-Public Land Mobile radio Network (PLMN)
13
. A representative, packet-switched, external core network shown as cloud
14
may be for example an IP network such as the Internet. The core networks are coupled to corresponding network service nodes
16
. The PSTN/ISDN network
12
and other PLMN network
13
are connected to a circuit-switched core node (CSCN)
18
, such as a Mobile Switching Center (MSC), that provides circuit-switched services. The UMTS
10
may co-exist with an existing cellular network, e.g., the Global System for Mobile Communications (GSM). The packet-switched network
14
is connected to a packet-switched core node (PSCN), e.g., a General Packet Radio Service (GPRS) node
20
tailored to provide packet-switched type services in the context of GSM which is sometimes referred to as the Serving GPRS Service Node (SGSN). Each of the core network service nodes
18
and
20
connects to a UMTS terrestrial radio access network (UTRAN)
24
over a radio access network interface. The UTRAN
24
includes one or more radio network systems (RNS)
25
each with a radio network controller (RNC)
26
coupled to a plurality of base stations (BS)
28
and to the RNCs in the UTRAN
24
.
Preferably, radio access over the radio interface in the UMTS
10
is based upon wideband, Code Division Multiple Access (WCDMA) with individual radio channels allocated using CDMA spreading codes which may each include both a channelization code and a scrambling code. Of course, other access methods may be employed like the well known TDMA access used in GSM. WCDMA provides wide bandwidth for multimedia services and other high transmission rate demands as well as robust features like diversity handoff and RAKE receivers to ensure high quality communication service in a frequently changing environment. Each mobile station is assigned its own spreading code in order for a base station
28
to identify transmissions from that particular mobile station. The mobile station also uses its own spreading code to identify transmissions from the base station either on a general broadcast or common channel or transmissions specifically intended for that mobile station. That spreading code distinguishes the spread signal from all of the other transmissions and noise present in the same area.
Different types of control channels are shown bridging the radio interface. For example, in the forward or downlink direction, there are several types of common control channels including a general broadcast channel (BCH), (there is only one broadcast channel per cell), a paging channel (PCH), and a forward access channel (FACH). In the reverse or uplink direction, a random access channel (RACH) is employed by mobile stations whenever access is desired to perform location registration, call origination, page response, and other types of access operations.
In general, each radio controller includes a memory coupled to data processing circuitry that performs numerous radio and data processing operations required to perform its control function and conduct communications between the RNC and other entities such as the core network service nodes, other RNCs and base stations. Data processing circuitry may include any one or a combination of suitable programmed or configured general purpose computer, microprocessor, microcontroller, dedicated logic circuitry, DSP, ASCI, etc. The base station similarly includes data processing in control circuitry, which in addition performs processing operations relating to communications with the RNC, performs a number of measurements in control operations associated with radio base station equipment. Data processing, memory, and transceiving circuitry is employed in each mobile station. The mobile station also includes a user interface with a speaker, microphone, keypad, display, and is typically powered by a battery.
Each base station shown
FIG. 1
may include one or more physical sectors, and each sector provides coverage for a certain geographical area associated with the base station. Referring to the example in
FIG. 2
, each of three sectors
1
—
3
has a corresponding antenna(s), transceiving hardware, and data and signal processing hardware to permit wideband-CDMA communications with mobile stations. In the present invention, each sector is mapped to one or more logical cells, and each cell may have one or more radio frequency carriers. For the example in
FIG. 2
, each sector includes four carriers f
1
-f
4
. Cell
1
is mapped to a base station sector with cell carriers f
1
and f
2
; cell
2
is mapped to cell carrier f
3
; and cell
3
is mapped to cell carrier f
4
. Neighboring cells can also have the same carriers.
Further understanding of the cell definition in the present invention is outlined in the example illustration of potential components of a single base station cell in FIG.
3
. The cell includes a primary carrier and zero or more secondary carriers that primarily provide additional traffic channels. Each carrier can encompass a wide frequency band, e.g., 5 MHz, in a WCDMA system. The primary carrier of a cell has one primary spreading code and zero or more secondary spreading codes. (A spreading code may include both a scrambling code and a channelization code; however, the details of specific CDMA codes are not essential to unde
Eriksson Göran
Ögren Mikael
Nixon & Vanderhye P.C.
Telefonaktiebolaget LM Ericsson (publ)
Tran Pablo N.
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