Looking at the older document and the RRDB - and assuming that the channel lineup has not changed too much - we would be looking for the following talkgroups / channels for Texarkana AR Police
Ch 1 - "Central" - primary dispatch channel
Ch 2 - "Info" - warrant checks etc
Ch 3 - car to car channel
Ch 4 - car to car channel
Ch 5 - car to car channel - possibly linked to Texas - possibly DTG 26030 on AWIN
Ch 6 + 7 + 8 - "Tac" 1 / 2 / 3 - for large scale incidents
Ch 10 - CID
Ch 11 - Narcotics
in addition they had channels for Admin + Animal Control + Jail + DPW
there were also Incident Command Channels and the Troop G EMS channel
they had 1 backup channel on AWIN to backup the failsoft channel
they also had the the ICALL channel and the 4 ITAC channels in direct mode in their radios - they could also serve as backup channels and as coord channels with Texas units
It is possible that they use the Texas TRS as their primary backup now.
It is also possible that Texarkana Texas and Bowie County Texas have backup channels on AWIN now.