Expected latency on 450 MHz?


I've deployed a 10 kms PTP link with CnReach N500 450 MHz. the BW channel is 12,5 KHz the AP is set to 32QAM. the RSSI is -79 dBm with a RF throughput (14.1/17.6 kbps) and latency min/avg/max = 207/302/448 ms.

I know this is a narrow band and it doesn't works as 900 MHz but can anybody tell me if the latency is good for this band or little higher? (I need to use ethernet protocol for PLCs)

I've replaced a 900 MHz to this 450 MHz link because of obstructions.

thanks in advance.