systems and 4800 baud control data mostly used on UHF and 900 MHz. This comes in 2 different types, the 9600 Baud control data commonly used on 800 MHz. Most scanners these days only require the current Control Data channel for many of the P25 and Motorola trunking systems to track them.ĮDACS is a trunking system originally sold by General Electric as a competitor with Motorola Type 1 and later Type 2 systems. Phase 1 allows a single conversation on a voice channel while Phase 2, a form of TDMA, allows 2 on each channel, effectively doubling the capacity of the system. There are two main types of P-25 Phase 1 and Phase 2 (or Phase I and II). P25 voice is also commonly used on conventional (non-trunked) channels as well. Harris designed systems can use any of the channels for control data and some of these rotate the control data regularly. On Motorola systems the Control Channel rarely changes and there are only 2 to 4 channels that they would rotate to if one becomes unavailable. One way to tell a Motorola designed system apart is by the control channels. The system was designed to be interoperable between the several vendors but often they add features that only they can provide so as to rope in customers to continue buying their radios instead of radios from other companies. The format was developed by and for APCO and is licensed from them. A later version of Type 2 trunking, called APCO P16, used the same Type 2 control data but allowed either analog or digital modulation.ĪPCO P25, as we discussed last week, is an all-digital format sold by several manufacturers, including Motorola, Harris and others. Some Type 1 systems were upgraded, either to Type 2 or to a hybrid system that allowed both Type 1 and Type 2 radios, this was commonly referred to as Type 2i. Type 2 systems could have more than 65,000 individual radio ID’s and thousands of Talkgroups. Motorola developed what was called Type 2 trunking that used a similar 3600 baud control data signal but removed the restrictions about Fleets and Subflleets and removed many of the limits on radios. In time it was found to be too limiting, it restricted the number of subfleets and radios that could be accommodated within the Fleets. The original Type 1 systems used a 3600 baud control data signal and a Fleets/Subfleet programming style. “Motorola” trunking systems include Type 1, Type 2 and Type 2i systems. I choose to use the easier to understand mnemonics of 1 and 2 rather than the more correct I and II for some of these systems. This week we will discuss some other formats of trunking. Earlier we discussed the differences between Type 1 & 2 and Phase 1 & 2 trunking systems.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |