FI109318B - Method for measurement of signal power - Google Patents

Description

109318

Method for measuring signal power - Förfarande for mätning av signaleffekt

FIELD OF THE INVENTION

The invention relates to a method for measuring the quality of a radio link in a radio packet data connection of a telecommunications cellular system 5. In particular, the invention relates to a method as mentioned in the preamble of claim 1.

BACKGROUND OF THE INVENTION

General Packet Radio Service (GPRS) is designed to transmit data using packet switched connections. The GPRS system 10 is intended to be added to existing GSM networks. It will also be used in the upcoming UMTS (Universal Mobile Telecommunication System). The packet data services provided by GPRS are ideal for services that are not real-time, such as e-mail or file transfer services.

15 GPRS has two new network elements available compared to GSM, that is, two different types of GPRS support nodes or GSNs: the Serving GPRS Support Node SGSN and the Gateway GPRS Support Node GPRS. ). Hierarchically, SGSN is also a "..." role as the Mobile Services Switching Center MSC. SGSN.n:. '·; 20 main function is to serve mobile stations, i.e., to track the location of mobile stations:: * · the SGSN is connected to the access point subsystem via the Gb interface The GPRS gateway support node GGSN connects to networks outside the GPRS network, such as the Internet or the X.25 network. ... 25 can be connected to the same physical device, or they can be implemented with separate physical devices! " internal devices. Further, GPRS subscriber data is stored in Home Location Registers *: · 'HLR (Home Location Registers).

When data packets for a mobile station arrive from an external network, they are first received by the GGSN, which routes the packets to the mobile station serving the mobile station.

· 30 for GSN. If the GGSN has no information about the SGSN serving the mobile station, the GGSN

* »« May request mobile location information from HLR. The SGSN sends packets to the mobile station through the base station subsystem.

2 109318 The system supports three different categories of mobile devices. A Class A mobile station can simultaneously use both GPRS and circuit switched services. The Class B mobile station monitors the control channels of both GPRS and other network services at the same time, but may use only one service type at a time, i.e., either circuit-switched or circuit-switched connections. A Class C mobile device can only use GPRS services.

The GPRS system supports three mid-range access modes: Dynamic Allocation mode, where the system distributes transmission channels on only one channel at a time, 10 - so-called. Extended Dynamic Allocation mode, in which a rigid system distributes broadcasts over a certain channel group, and - so-called. Fixed Allocation Mode, in which the mobile station is assigned permanent channels and radio blocks for transmission.

The network defines the middle-class access mode and channels and signals them to the mobile station typically at the beginning of the packet data connection.

In dynamic access mode, the mobile station monitors downlink radio blocks to detect an uplink state flag assigned to it, the Uplink State Flag. The up space flag field is included in the header of each data block in a downward direction. a packet data channel, a PDCH (Packet Data Channel), for example, a control channel, and the USF signals which mobile station is now transmitting on a corresponding uplink PDCH. When a mobile station detects its own USF downward • · Y ·; In the PDCH data block corresponding to the uplink ':' *: PDCH assigned to the mobile station, the mobile station transmits the data block on the uplink PDCH. The actual data carried by the downlink data block may be directed to a different mobile station: '·': 25 than that referred to by the USF of the data block.

In extended dynamic access mode, transmitting a USF value assigned to a mobile station * * '·' means that the mobile station may be transmitted on that PDCH and on any larger number of PDCHs assigned to it.

* * * * »

When using dynamic access mode or extended dynamic access mode, two mobile stations must receive a downlink RLC block; Y to the mobile station to which the actual data of the RLC block is transmitted and to which the uplink transmission permission is granted by the USF contained in the RLC block. When adjusting the downlink transmission power, the requirements of each mobile station must be taken into account. In the current GPRS, however, only those mobile stations that receive downlink payload data generate measurement reports on the quality of the network reception. If the mobile station to which the USF is intended does not receive downlink data at that time, the network will not have any information as to which transmission level is sufficient for good reception quality in that mobile station. Therefore, the mobile station concerned 5 may not detect its USF and its uplink transmission.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a method which avoids the disadvantages of the prior art. It is a further object of the invention to provide a method in which a sufficient transmission power can be determined for a radio block to receive both the mobile station for which the radio block is intended and the mobile station for which the USF flag included in the radio block header is intended.

The objects of the invention are achieved by arranging the mobile station to measure the connection quality of the blocks containing control information directed to that mobile station.

The method according to the invention is characterized by what is disclosed in the characterizing part of the independent claim. Other preferred embodiments of the invention are described in the dependent claims.

·. According to the invention, the quality of the reception of data blocks containing downlink control channel data containing control information directed to the mobile station is measured by the mobile station 20, which further reports the measurement data to the network. Basic measurement data •; on the road, the network controls the transmission power of packets transmitted on the DL control channel such that; 'All mobile stations with packet data can successfully decode »*»' packets

ART CATALOG

The invention will now be described in more detail with reference to the accompanying Figure 1, which illustrates a method according to a preferred embodiment of the invention. ·: I.

: '' ': DETAILED DESCRIPTION

Figure 1 shows a signaling period between two mobile stations 10a, 10b and a cellular network 30 in accordance with a preferred embodiment of the invention. Figure 1 illustrates signaling in a situation where mobile station MSI, 10a already has an active pai 4 109318 chain data connection to the network, and mobile station MS2, 10b, is establishing a packet data connection to the network.

In step 100, the second mobile station MS2 10b transmits a connection request message CONNECTION REQUEST to the network to establish a packet data connection for transmission of up-5 data. The network responds by sending a contact message CONNECTION INFO to the 105 MS. In the message, the network indicates which channel MS2 can use, and in this example, it further indicates that the MS2 must perform reception quality measurement of downlink data blocks containing control information directed to MS2. In addition, the network may report as-10 dense MS2 should measure and report reception quality, for example, each data block containing control information directed to MS2, one such second data block, one such fourth data block, or more generally, every Nth data block, wherein N may be a positive integer in a given region, for example, a multiple of two in a specified region.

The connection establishment may also proceed in a number of ways other than those illustrated in steps 100 and 105 of FIG. 1, and may further include, for example, sending many other messages.

In the example of Figure 1, the network grants MS2 10b permission to send a data block, which MS2 performs in step 110. The network responds by sending an acknowledgment message 115. 20 ACK. Upon receipt of the acknowledgment message, MS2 measures the reception quality and • reports 120 reception quality to the network. In this example, it is assumed that the acknowledgment message. The network informs that MS2 is still authorized to send data, which MS2 does at step 125. Again, the network responds by sending an acknowledgment message at step ... 130. This time, the network does not indicate that MS2 can continue sending data, which MS2 sends 135 a measurement report I · · 'based only on the receipt of the acknowledgment message. In the next step 140, the network transmits a data block to the first mobile station MSI and includes in the block header a USF assigned to the second mobile station MS2. Thus, MS2 measures the reception level of the data block transmitted in step 140 and reports the quality in step 145. MSI reports the reception level of the data block 30 in step 150. Since the network signals the USF to MS2, MS2 transmits >

* ·

The example in Figure 1 assumes that the network advises MS2 to report to the network. the reception level of each block containing control information directed to MS2. However, this does not in any way limit the invention, and many other measurement and reporting densities can also be used in various embodiments of the invention. Measuring and reporting each block containing control information directed to MS2.ile would result in an extremely high frequency signaling in a practical embodiment of the invention.

The invention has several advantages. For example, measurements performed by a mobile station receiving downlink RLC data blocks and a mobile station receiving a USF flag in the header of a downlink RLC block allow the network to determine its downlink power to an optimal level that satisfies both downlink RLC block receiving mobile stations and at the same time cause minimal interference to other parts of the network 10.

The mobile station, which measures the reception quality of the blocks containing control information assigned to the mobile station, may report the reception quality to the network, for example, using the same quality parameters as in known quality measurements. Parameters such as C value, X QUAL, SIGN VAR, and LOVE ...

15 IJLEVEL TN7, which are typically transmitted, for example, in a downlink packet accept / reject message PACKET DOWNLINK ACK / NACK, which acknowledges receipt of a payload data block by the mobile station.

The network may change the measurement and reporting periods, for example, by attaching a command to an acknowledgment message sent to the mobile station.

I * 20 The network may also indicate in the connection messages, for example, system information messages, whether the mobile station should send a measurement report message. MEASUREMENT REPORT in first uplink: ": block.

• t · •: ·. The various message names used above, such as MEASUREMENT REPORT, are provided by way of example only, and the message names used in this specification are in no way limiting the invention.

'' ': It will be clear to one skilled in the art from the above description that the invention. many variations can be made within the scope of its inventive idea. A preferred embodiment of the invention has been described in detail above, but of course many different modifications and variations can be made, all of which are within the spirit and letter of the invention.

Claims (2)

109318 1. A method of measuring in a digital cellular communication system, characterized in that the method comprises the steps of measuring the quality of a data block of a data block in which the information directed to that mobile device consists of control information directed to that mobile within the meaning of. A method according to claim 1, characterized in that said control information is a USF value assigned to the mobile station. 10 Patent Claims 1. Mätförfarande i et digitalt cellradiosystem för Telecommunication, telecommendation av att förfarandet innefattar steg där mobilstationen mätteren quality hos mottagningen av et datablock i flogging information account den mobilstationen be-stär av styrinformation à lille you give a styrinformation, men avsett för en a mobilstation. f 2. Förfarande enligt patentkrav 1, kännetecknat av att nd styrinformation • · · · · · · · · · · · · · · · · · · · · · · · · · · · ·: j * * »t * ·