FI97763C - A method of lining data transmitted from a wireless channel through a radio channel in a paging network - Google Patents

Description

97763

A method for routing information transmitted from wireless base stations on a radio channel in a paging network. - Förfarande för linjering av frän trädlösa stödstationer genom en • radiokanal sänd data i ett personsökarnät.

The invention relates to a method for routing information transmitted from wireless base stations on a radio channel in a paging network, which includes base stations for transmitting paging messages by radio and a central station for controlling the operation of the base stations.

Base station data consists of error data, base station diagnostic data, and measurement data.

When using a radio channel to transmit base station information from base stations to a central station, the unreliability of the connections, i.e. possible interruptions and other interference, must be taken into account. When using the same radio channel as for paging, too much of the channel's capacity must not be reserved for data transmission so as not to interfere with the transmission of actual paging.

Immediate routing can be used for radio communication between base stations, with all base stations repeating everything they hear. Efficiency is poor. The transmission of base station data takes up a considerable part of the data transmission capacity of the base station network.

The object of the invention is to improve the above-mentioned method so that the transmission of base station information to be transmitted from base stations to a central station using a radio channel can be routed adaptively and optimizing the radio time used.

This object is achieved on the basis of the features set out in the appended claim 1.

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Preferred embodiments of the invention are set out in the dependent claims.

Compared to implicit routing, the routing according to the invention (so-called multihop routing) can be used to optimize the use of radio time so that the smallest possible part of the radio channel's capacity is reserved for data transmission (max. 4% of the capacity). Adaptive routing avoids interruptions in network operation caused by network outages and other disturbances, i.e. reliability is good.

The invention will now be illustrated with reference to the accompanying drawings, in which Figure 1 is a block diagram of a paging system in which the routing method according to the invention can be applied; Figure 2 shows a schematic diagram of a wireless base station network; Figure 3 shows a flow chart of the operation of the paging area controller PAC in routing; and Figure 4 shows the matching of base station information transmitted by different base stations to the paging holiday.

In the block diagram of FIG. The PAC and PNC are connected to the OMC, from which the system functions can also be monitored and controlled manually.

97763 3

Figure 2 shows a schematic diagram of a wireless base station * network using the so-called multihop routing.

‘Multihop routing refers to a system in which base station information transmitted from each base station (PBS) is transmitted through other base stations to a node base station, which transmits the data to the PAC, e.g., via a fixed connection. Figure 2 shows PBS01 as a node station.

A route is established for each base station along which its data can be delivered. In Figure 2, e.g., PBS32 messages are routed; 32-24-11-01-PAC and PBS33 messages; 33-25-12-01-PAC.

Routes are optimized to minimize the load on the network's data transmission capacity. Routing is a dynamic, repetitive optimization in nature, ie variations in network conditions are constantly taken into account, in which case the network structure may change during operation.

Wireless paging system routings and timings are performed in PAC'11a, which has sufficient computing capacity for the purpose. The operation of the PAC in routing is described in the accompanying diagram (Figure 3).

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For each PBS, a table is kept by the PAC of the PBS it hears and those that may interfere with reception from the stations in question. This table is initially entered from the network 0MC. In Figure 2, PBS24 hears stations 11, 12, 23, 25, 31, 32, and 33. PBSs monitor the transmission of the other base stations they hear and report to the PAC any anomalies they have detected (e.g., new and removed PBSs).

The PAC calculates the optimal routings and updates the routing tables for the PBS via a satellite connection. The routing table tells 4 97763 at what point in time each PBS sends messages and which stations it forwards messages to. For example, the PBS24 table in Figure 2 states that it forwards the messages of PBS31 and PBS32.

PBS11 sends messages at agreed times, between searches. During every 10 minutes, a max. two 12 s time slots (Figure 4a). In this way, a max. 4%. In the first time slot, as many PBS messages as it can fit are sent, and if there are more messages, they are sent in the second time slot.

Within the time interval, the PAC gives each PBS an exact time when it starts sending its data packet (Figure 4b). First, a separate packet is sent and then received, forwarded packets. In Figure 4b, transmission packet B transmits its own packet B1 and the packet B2 to be transmitted.

Stations that do not interfere with each other can transmit at the same time. For simultaneous broadcasters, the PBS is allocated an equal amount of time, the duration of which is determined by the PBS with the most messages to transmit. In Figure 2, PBS31 and PBS32 cannot transmit simultaneously, but e.g. PBS22 and PBS24 can.

Since PBS24 has 2 station messages to transmit and PBS22 has nothing, the duration is determined by PBS24.

Within the time slot, when a particular PBS does not have a transmission queue, its transmitter is turned off and the receiver is turned on, allowing it to receive messages from other PBSs.

Each data packet has a synchronization field, a transmitting base station, a station identification number, information about the content of the message, and a checksum CRC (Figure 4c). If the message to be forwarded fails to receive (poor reception, invalid CRC, etc.), an error message is sent instead of the message stating that PBS and its own 97763 5.

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If the PBS disconnects from the network, the next base station informs the PAC (by sending an error message), which determines the routes around this PBS. The PAC forwards the information to the OMC. Disconnected PBS is detected in at least 10 minutes, which is the base station data transmission interval. Disconnection is interpreted to have occurred if no information has been received from the PBS on its departure shift. If the PBS25 is disconnected in Figure 2, the routing table of the PBS24 is changed so that it also forwards the messages of the PBS33.

When a new base station is connected to the network, it initially sends its own identification number in the time slot reserved for the new stations.

Those base stations that hear the new station forward a message to the PAC, which gives the new station the transmission time slot and routing information, and add the new station to the routing tables.

Claims (4)

1. A method for lining from wireless support stations through a radio channel transmitted data in a paging network, which includes support stations (PBS) for transmitting search messages via radio and a central station (PAC) for controlling the operation of the support stations, characterized in that: support station data from the support stations (PBS) to the central station (PAC) is transmitted via one or more support stations (PBS) and the support station data transmitting support stations (PBS) have an individual lining table which determines when the transmission is to take place and which support station's transmitted support station data shall be forwarded. Method according to Claim 1, characterized in that said support station data is transmitted at predetermined times (D) between searches (P). 3. A method according to claim 1 or 2, characterized in that, in said manner, radio messages for transmitting support station data are received at a node support station (PBS01) which interferes with a fixed data transmission connection with the cental station (PAC). Method according to any of claims 1-3, characterized in that the search area (PAC) checks are performed by said central station or its part, which counts the optimum alignments according to the information received from the support stations (PBS) and updates said align tables. to the support stations.