National Grid Wireless, formerly the BBC Home Service Transmission
Division, are a provider of wireless infrastructure and network services
to broadcasters and telecommunications operators. They currently have
approximately 3000 sites hosting equipment for Hutchison 3 (the UK 3G
network), Vodafone, Orange, O2 and T-Mobile and had a requirement to
provide a service to these users, charged on the basis of, amongst other
things, the amount of power used on each site. Therefore a wireless meter
reading solution was required. Additionally, as part of the value added
service provided to their clients, National Grid Wireless had an
additional requirement to be informed of loss of power to any of the sites
so that interruptions to any site could be kept within the contractually
This solution was provided with a system based upon the NHDS Messenger 62
(M62) remote meter-reading and remote monitoring units. The M62 unit has 8
meter reading inputs and 8 digital inputs for monitoring alarms as well as
the ability to monitor the mains supply. The unit uses the GSM mobile
phone network to report to the host terminal system.
Initially this system consisted of a single stand-alone PC running the
Messenger host terminal software package and monitoring just under 1000
M62 units. This provided an initial trial system prior to going live with
a system producing actual billing data for National Grid Wireless
The system was soon expanded however to run on a central server with
remote clients and a direct link from the host terminal system to the
Technical Operations Centre (TOC) system, a department responsible for
24/7 monitoring of the companies equipment and sites.
At this stage the Messenger system was deemed a mission critical system
and had to achieve the standards of fault tolerance, redundancy and
disaster recovery required of such systems within the company. To this
end, a duplicate system was installed at a backup site in Sutton Coldfield
so that in the event of a major disaster at the headquarters in Warwick
all operations could be brought back online from the Sutton Coldfield site
without loss of data.
The system is based around an Oracle 9 database running on a Windows
2000 based rack-mounted server.
Communications between M62 units and the system is carried out with
another Windows 2000 based rack-mounted server, running the standard
Messenger host terminal software configured as a modem server. This
software is installed to run as a Windows “Service”, thereby avoiding
the need for the server to be logged on as any particular user. This
allows the software to be loaded automatically in the event of the server
rebooting without user intervention.
Actual communications is handled by the use of a number of GSM modems,
connected to the modem server PC directly via a multi-port serial card.
Future expansion of the system is likely to lead to a direct connection
into the T-Mobile GSM network using a network pipe, thereby replacing the
need for any actual modems.
The modem server also communicates directly with the TOC system by TCP/IP
pipes. The server passes all relevant status and event data to two
different addresses, one for the main TOC system located in the same
building and one for the standby TOC system at the backup site at Sutton
Coldfield. This provides the TOC team with information regarding site
mains failures and restorations directly to their management system,
eliminating the need to run a Messenger client system in the TOC
department. The system also has the ability to automatically send SMS text
messages to on-duty field staff responsible for investigating and
correcting site faults. For information purposes, emails of such alarm
events are also automatically generated and sent to the personnel
responsible for installing and maintaining the Messenger units themselves.
Billing reports are created automatically at defined intervals and
forwarded to relevant parties ready for forward billing to National Grid
Wireless's own customers.
A number of client terminals, fitted with the standard Messenger host
terminal software, are also used in the system. This is to enable relevant
personnel to examine the current status of the Messenger units and to
reprogram parameters and view/search historical archives of system events.
A duplicate database server and modem server are located at the Sutton
Coldfield backup site ready to take over operations whenever required. The
database will soon be linked to the main database server as a replicated
database, where the data is kept in step with the main database so the two
systems can run in parallel, and hand-over to the standby system will be
The individual elements of this system are as follows:
This is the heart of the system where all the status and historical
data is stored. This is comprised of an Oracle 9 database management
system running on a Windows 2000 server PC.
The system contains 2 modem servers, one on the main site and one on
the backup site, to receive and make calls from/to the M62 units. Each
server consists of the standard host terminal software installed on a
Windows 2000 server PC mounted in a rack. The software is installed as a
Windows “Service” to avoid the need for user intervention in server
power up or the need for a server to be logged on for the software to run.
Although these terminals are not used with permanent monitors or
keyboards, as they are unmanned, they can be used as standard client
terminals if desired.
Standard Client Terminals
The standard client terminal software is used to provide system status
and the viewing of historical event data. Client terminals in this system
are usually used in an ad-hoc basis, where the software is run on demand.
Technical Operation Centre
The Technical Operations Centre (TOC) is the National Grid Wireless
department responsible for maintaining 24/7 monitoring of National Grid
Wireless equipment and sites. Two TCPI/IP pipes are established from each
of the modem servers to the TOC management systems (both the main system
and the backup system at Sutton Coldfield) to pass information regarding
the loss or recovery of power from monitored M62 sites.