This may seem like a simple topic but with the advent of digital transmission and network-linked repeaters in particular, as responsible radio operators we need to redefine our approach to the humble ‘pause between overs’ that we’ve become used to in the analogue world.
With analogue transmissions, either simplex or via a repeater, it’s been the adopted procedure to leave a short pause between overs (usually about 1-2 seconds) as a courtesy to other users who may wish to join the conversation or call another station. For the purpose of this guide, we’ve called it a ‘Standard Pause’.
Longer Pauses – why they are needed:
Whilst digital transmission & network linked repeaters offer us a wider and more varied range of networks and users, it’s not without its problems and limitations. One of those is Network Latency or delay.
Whereas analogue transmissions are almost instantaneous user to user, digital transmissions have an inherent processing delay as they travel through the network, which can sometimes be as much as 3-4 seconds in the worst cases. A good working example is if you have access to more than one repeater in your area. If you listen to the same Talkgroup on both repeaters, it’s unlikely that the two audio streams will be synchronised.
There are times when this delay is quite considerable, meaning that the person you’re listening to could well have actually stopped speaking by the time you hear them finish their over. It may only be 2 seconds, but it’s enough to cause potential problems for other users on the network.
It is therefore suggested that a longer pause of perhaps 4-5 seconds is allowed between the end of one over and the start of another. This should not only give enough time for the networks to ‘catch up’ as it were, but also provide some leeway for other users to break in, either to join your conversation, but perhaps more importantly, to switch between Talkgroups on the same Timeslot.
With the advent of cross-network access, the importance of leaving longer pauses has become more relevant due to the complexity of how the networks are linked and the inter-network delays. Occasionally a cross-network transmission has not to been relayed due to the network itself not having time to ‘reset’ – i.e doesn’t see the end of a valid transmission.
When using digital networks (of whatever flavour), it is recommended that the ‘pause between overs’ should be around 3-5 seconds. If you’re in QSO and are requested to leave a longer pause, please do so in a courteous manner. Leaving a long pause will not mean that you loose your slot to another Talkgroup – that’s why the hold-off timers with a 5 minute time-out were introduced.