Motorola MTM800 Product Information Manual page 80

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Additionally a user is able to send a call back request to any terminal via menu functionality.
Call Me Back requests are received as normal status messages and like any other status message,
the user is able to respond when viewing the message.
8 Packet Data (TMO)
In TMO the terminals provide a TETRA bearer service for applications that use the IP protocol.
External applications are able to use this service by connecting via the PEI interface.
External applications will be able to use this service by connecting via the PEI interface, as
described in Paragraph 13 "PEI Characteristics".
8.1 General
The terminal supports TETRA standard multi slot packet data using the IP network layer protocol.
Packet data applications will reside internally, over UDP, or in an external device connected to the 8
wire RS232 data port on the terminal. Communication to the external device is initialized using AT
commands and once connected the external device may request PPP mode and will then operate in
PPP mode until the data connection is terminated.
8.2 Connectivity
The system provides point to point IP connectivity allowing the following datagram exchanges:
• Terminal <-> External Equipment (TE2) - PC etc.
• External Equipment (TE2) <-> Network (via Terminal)
8.3 Packet Data Terminal Interface
The terminal:
• Supports only IP version 4 packets
• Routes datagrams independent of the protocol sitting on top of IP
• Supports an MTU of 1500 bytes
• Provides a best effort delivery service, but if delivery fails, the originating user application will
be informed, if possible, by sending back to TE2 an ICMP message
8.4 Voice + Data Support
The terminals are able to alternate between voice and the packet data service, but do not support
simultaneous voice and packet data transmissions.
8.4.1 Voice Only Mode
This is a user menu selectable option that is remembered at power up and if selected, packet data
functionality is disabled. If the packet data service is active when voice mode is selected, then the
packet data service will be disabled and the PEI will operate in local mode only. This will allow TNP1
operation which does not require PDP context activation.
6866537D87-F Chapter 2 - MTM800 Product Information Manual
Services and Feature Description
September 2008