We have run into quite a few “green” salespeople lately. They seem to be telling customers that by moving to a MOTOTRBO Conventional or IP Site Connect (a.k.a. DMR Tier II) system that they are getting the benefits of trunking. This is simply NOT the case.
DMR utilizes TDMA to allow different users to share the same channel, by dividing it into “time slots”. In a standard configuration, talkgroups are statically assigned to time slots.
Let’s assume an example case with the following:
- 20 administrative talkgroup users
- 10 security talkgroup users
- 10 maintenance talkgroup users
Since the administrative talkgroup has more users, you decide to assign it to time slot 1. You decide to assign the other two talkgroups to time slot 2.
If security is using their radios and maintenance needs to talk, can they? No. Why? Because both groups are statically assigned to time slot 2. If security is using time slot 2, maintenance cannot. This does not change whether or not time slot 1 is in use. So, while it is true that “you’ll have double the capacity“, you won’t have an efficient way to use that capacity.
In order to efficiently use capacity, you need trunking, which allows for talkgroups to be dynamically assigned. If you are looking to efficiently use capacity, please contact us at (804) 625-4233 or sales AT richmondrf DOT com.
Jamie, that is the beauty of Hytera DMR. WE have the ability to use the Available OPEN SLOT at the time, while Motorola DMR is exactly as you describe! We call this DMR TRUE 2 SLOT. We also have the ability to make it act like TRUNKING when connecting several repeaters together. This allows the radios to utilize ANY of the OPEN TIME SLOTS in the entire stack of repeaters. The radios basically listen for the open slot, and then use it. This also makes the system act like trunking but without any control channel. We use this in a wide area configuration and can even go multi site. This is called XPT or XTENDED PSEUDO TRUNKING. HYTERA has taken DMR to a whole new place in the industry!