Codan Radio P25 Training Guide - Manual (Page 46)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 3: P25 Technical Information Page 38
Location Service Host System
The Location Service Host System (LSHS) resides outside of the standard P25 Radio System Network.
The LSHS may use the location information to provide subscriber location mapping functionality
(showing users on a map program). The LSHS can also issues commands to the subscribers to obtain
location information, or to confi gure the subscribers triggering conditions, if a bi-directional request/
response protocol is used. The specifi c LSHS capabilities are outside the scope of the P25 Location
Service specifi cations.
The LSHS might be hosted by (reside in) the Fixed Data Host (FDH), or the Mobile Data Peripheral
(MDP). Depending on the subscriber manufacturer’s design, the LSHS may be a part of the actual
subscriber (integrated map display for example).
Fixed Data Host
The Fixed Data Host (FDH) is the endpoint of a P25 radio system network that contains or communicates
with the Location Service Host System (LSHS). The FDH interfaces to the RF Sub-System using the
Data Host Interface (Ed) of the P25 Standards, and has an IP address. The FDH receives location
information from the subscriber (on a UDP port), uncompresses and sends it to the LSHS. When
a bi-directional request/response protocol is used, the FDH will receive commands from the LSHS,
compress them and send them to the subscriber.
Mobile Data Peripheral
The Mobile Data Peripheral (MDP) interfaces to the subscriber using the Data Peripheral Interface (A)
of the P25 Standards, and has an IP address. The MDP may contain or communicate with the LSHS,
and might contain (part of) or communicate with the LIS. The MDP receives location information from
the LIS and sends it to the subscriber, encapsulated in UDP/IP over the A interface. The MDP also
receives location information from the subscriber, uncompresses and sends it to the LSHS. When
a bi-directional request/response protocol is used, the FDH will receive commands from the LSHS,
compress them and send them to the subscriber.