Short range radio

Live data is essential in competitions for delivering information to organisers or speakers. It enhances the overall experience for spectators and competitors. For spectators, it is far less spectacular to watch an event like orienteering, MTB Enduro, trail, and so on, by having only the final results. The competitors in the forest or on the track might at some stage pass by the competition arena, but most of the time they are invisible for the spectators.

With the use of additional SPORTident devices (data transmitter and data receivers), live data can be produced to provide more information for the speaker and the public, like the position in the race of the participants, allowing them to make race predictions and to analyse the respective split times.

The radio data transmission between the SPORTident devices is done using a proprietary protocol and with a short range.

The collected data can be processed by a web service or used directly by evaluation software (see section Live data).

The following SPORTident devices provide radio transmission via SRR (short range radio):

The following sections describe the devices and their configuration in detail.

The SPORTident Short Range Radio (SI-SRR) enables wireless transmission of SPORTident data records over distances of up to 8 metres. The radio is working in the licence free 2.4 GHz radio band and can be used worldwide.

SI-SRR uses two radio channels (named ‘red’ and ‘blue’) to achieve a robust data transmission with a low error rate. The BSF8-SRR station, the SIAC and the SI-GSM Modem can transmit or receive on both radio channels. The SRR USB Dongle can only receive on one radio channel. This can be configured.

A data receiver device such as the SRR USB Dongle or the SI-GSM Modem can manage up to eight logical radio links. However, there can be any possible numbers of data transmitter devices such as stations BSF8-SRR or SIACs in the service area.

Radio transmission must be activated in the transmitters and receivers. This is possible via the configuration using Config+. For a detailed description, see the sections on the devices above.

The power consumption of the BSF8-SRR station and also of the SIAC increases significantly when they transmit data by radio. Therefore, only activate the radio when you really use it. Make sure that the sender also has the possibility to transmit its data to a receiver. Otherwise, the transmitter will repeatedly try in vain to transmit its data and consume energy in the process.

The receiver must be placed as close as possible to the transmitter. The maximum transmission range between a non-moving transmitter and receiver is approx. 8 metres. At the checkpoint (orienteering) the receiver can be mounted at the same post as the SI-Station (BSF8-SRR Station or a SI-Station in beacon mode with active radio).
If participants pass a checkpoint at high speed and in a given direction, the receiver should be placed approx. 6 metres in the direction of passing behind the checkpoint. For example, in a MTB competition, the receiver (modem) is placed 6 metres behind the checkpoint (intermediate or finish time) in the direction of riding.

Sufficient distance (at least 30 metres) must be allowed between two receivers to avoid collisions and loss of data.
If two SRR USB Dongles are in close proximity, both should receive on different radio channels. We recommend the simultaneous use of two SRR USB Dongles, one on the radio channel red, the other on ‘blue’, to improve data transmission.

Try to reduce the number of records a SIAC has to transmit at once. This reduces its energy consumption and increases the transmission quality. If you want to use the send all unsent records setting, place receivers at several checkpoints and have them transmit a few records at a time. For example, at an MTB Enduro competition, the SIAC should transmit records at the finish timekeeping of each stage. It then only has to transmit two records, one for the start time and one for the finish time.

If a BSF8-SRR station is configured as a beacon control, the radio is activated and is now punched by a SIAC in the contactless way, the SIAC transmit their data to the receiver. In this case, the data is not transmitted via the station’s radio module.
At this station, an SI-Card can be punched directly and an SIAC indirectly at the same time. Both SI cards store their stamps. There may be conflicts in the radio transmission and only one of the two stamps may be successfully transmitted to the receiver, as the station and the SIAC are now sending data simultaneously.

When using an SI-GSM Modem at locations with poor network coverage, the modem can only transmit the data to the web service and the evaluation software with a delay or not at all if the connection is interrupted.