Full duplex communication – does it really make a difference?
Some radio solutions only offer full duplex at the base, not the remote, but does it really make that much of a difference? The answer is a definite yes!
Capacity
The most obvious advantage offered by full duplex communication is capacity. Due to the fact both the downlink and uplink channels can be used 100% of the time, this will effectively provide a doubling of system capacity compared to half duplex. (Note that the biggest capacity gains are in scenarios where the traffic volumes for the uplink and downlink are similar.)
While combining full duplex bases with half duplex remotes can alleviate some of hit to data throughput, it is an unavoidable situation that half duplex remote radios still cannot send uplink data while receiving downlink data.
If system capacity is a concern for you – either now or looking into the future – it makes far more sense to invest in a full duplex communication system from day one.
Faster reaction for IP Protocols & Adaptive modulation
Most utilities are shifting towards the use of IP protocols to communicate between their assets as part of grid modernization. These protocols struggle to perform well in a half-duplex environment.
In a full duplex system, IP protocols can make use of a feedback path to dynamically adjust to the environment. Adaptive modulation also can react more quickly in a full duplex environment to either dial up or down the modulation in response to RF conditions. A system which can rapidly adjust to suit conditions brings a level of resiliency in the transfer of mission critical data.
Uplink availability
In a system with multiple services running over it (for example, SCADA, ADMS, metering and NMS) the master radios can be communicating to multiple remotes at the same time. In a half duplex system, significant delay would be introduced due to the remote radios’ inability to ‘listen and talk’ at the same time. Where there is delay, your chance of retries increases which then further reduces the overall system data capacity.
Notably, in a full duplex system the uplink can still be used while a downlink broadcast is being sent or when system control information is being sent on the downlink.
In summary, if you’re looking for a system which offers increased data capacity and is better positioned to dynamically adapt, selecting a system which supports full duplex communication is imperative.