Sutron Corporation X-Link Operations & Maintenance Manual, Rev 1.63 5/24/2016 pg. 142
The delivery of data via the internet is via e-mail and/or direct IP. Sutron uses
Direct IP in its SutronWin and Tempest products. The protocol delivers the
messages within 5 seconds of their reception by the gateway. Sutron only uses
the e-mail delivery of messages in tests. Sutron’s AutoPoll cannot receive Iridium
messages.
To keep communications costs low, Sutron offers several formats for its
messages. The formats differ primarily in the amount of overhead data that is
provided in the message.
15.1.2.
GPRS
GPRS stands for General Packet Radio Service. This service is provided by GSM
(Global System for Mobile Communications) cellular communication systems to
support data communications. GPRS is the most widely supported cellular
technology. International service is offered in 130 countries. A few areas
support CDMA in place of GPRS, a competing standard. For this reason, Sutron
offers both GPRS and CDMA models of X-Link.
Warning: cellular coverage is not available in all areas. Be sure to try out a
normal cell phone at every location you plan to use to make sure the area is
covered. Beware of coverage maps as they may not properly reflect your
ability to communicate at a specific location.
GPRS services are charged based on the amount of data that is sent. The data
includes overheads to make open connections, route messages, acknowledge
messages etc.
The GPRS modem requires a SIM card to
identify and authenticate the modem on the
network. The network characteristics of the
modem including its IP address and
accessibility are all set by the SIM card that is
used and the Access Point Name (APN)
associated with it. These network
characteristics include the IP address that determines how the station can be
accessed via the Internet.
When you use a Sutron-provided SIM, your station will be assigned a static,
private IP address. This type of IP address allows two-way access to the station (if
you’ve turned Listening ON) while protecting the station by giving it an address
that is only accessible via VPN (Virtual Private Network). When you get a SIM
card from anywhere else, it may or may not support GPRS, and you will probably
be limited to communicating with the station only when it communicates with
you.
