Fylde Trunked Radio Products.

TSC Control Unit

The Trunking System Controller Channel Card
The TSC channel card has been designed specifically for MPT1327 applications and thus there is no compromise in either performance or reliability. Each card allows all the major MPT1327 trunked radio functions to be performed. One TSC card is required for each radio base station (repeater) in the system. Connection can be achieved with many different base station types allowing the channel to operate as an MPT1327 channel. Addition of the Fylde TSC to a system allows the upgrade of existing radio channels (for example those being used for CBS operation) to MPT1327 operation in a cost effective way.

 A Single Channel MPT1327 Repeater
With Fylde Trunking, it is possible to use a single channel base station. No other processors are necessary. Starting up a MPT1327 system could not be simpler or more cost effective. A single TSC channel card and base station will radiate MPT1327 control channel signalling until it receives a speech call request. It then converts to a Traffic Channel for the duration of the call, returning to control mode upon termination.

Such a system is very useful in -

• Coverage planning - allowing quick and easy relocation.
  
• Live customer demonstrations.
  
• New start up systems to present a consistent grade of service as the system expands.
  

Channel Configuration
With identical hardware and software in each TSC channel card, adding or removing channels is simplicity itself and can even be carried out while the system is live with little or no disruption to the users. The TSC channel cards communicate via a simple 2-wire high speed connection and the addition or removal of this 'SIO Bus' link is the only operation necessary. Up to 24 channels can be connected together on each site in this way.

Reliability
Unlike most radio systems where a central processing unit controls the entire system, Fylde have designed a fall-back mode based on 'Gradual Degradation'. In practise, this means that if a channel fails, the other channels are able to communicate and will automatically reconfigure to 'ignore' the faulty channel. When this channel returns to service, reconfiguration will again, automatically return it to the pool of channels. A five channel system can therefore suffer up to four complete channel failures and still offer service.

Reliability
The MPT1327 protocol is an 'open standard', this means that any MPT1327 compliant mobile will operate on the Fylde infra-structure. This gives Fylde system operators the opportunity to choose the mobile units that are most suitable in terms of cost and features.

Functions of the TSC Channel Cards
The TSC cards, alone, will carry out the following functions -

All MPT1327 function except inter-site call set up and call divert. (These require an RCP or SSIU).

SCI03 System Controller

To add a user interface into the Fylde trunked site, it is necessary to add two products. The System Control Interface - a 3U 19" rack mount unit and Syscon- PC based System Control software linked via hard-wire RS232 or modem connected to a PSTN circuit at the radio site..

As its name suggest, one of the functions of the SCI is to connect the channel cards to the outside world. This then enables both input and output of data to the site.

The SCI03 is part of the new line-up of improved Fylde Infrastructure.

Data Output

Stores billing records on a call-by-call basis.

Call statistics to MPT1318 are compiled over a rolling 24-hour period.

Individual validation of radio units.

System alarms are presented to the system terminal Syscon

Data Input
Individual validation of Radio Units - Without the SCI every mobile is white-listed (i.e. all access) with the SCI, every mobile is black-listed (i.e. no access) until individually validated onto the system.

Alteration of up to 16 'palettes' of operational control parameters, allow call times, queuing, system availability, etc. to change automatically throughout the day/night within pre-defined time periods. This allows 'fine tuning' of the system to be carried out in real time from a PC terminal.

The new Fylde SCI, the SCI03e shown here offers users the following advantages over the SCI02.

Configuration of SCI parameters via PC to Port B to program the onboard flash RAM.
Faster communications links between the SCI and RCP.
On-board memory expandable up to 16Mbytes.
Minimum memory configuration allows up to 24,432 packets of billing data to be stored.
Maximum memory configurations allow up to 127,000 packets of billing data to be stored at each SCI.
On-board memory partitions in software.
Fully EMC/LAD compliant.
Fast ESN on registration check.
Internal rack temperature monitoring.
38 extra control bits available per subscriber (e.g. more control over individual call times)
5 TEL outputs to drive auxiliary functions (e.g. check on diesel generator operation).
5 auxiliary inputs for site alarm functions (definable as TTL or analogue from 0 to 51v).

The new SCI has passed all mandatory European EMC tests for emissions and immunity with flying colours. In fact, the pass margin was above 15dBuV/m right across the test frequency spectrum.

Features
Should the radio site suffer a complete power failure, all data held by the SCI (user defined call parameters, billing data, mobile validations) are stored in battery backed RAM within the SCI for up to 1 year. This then allows an engineer to access the equipment,remove the RAM module and retrieve the data off-site. This ensures that precious call billing data is not lost.

User Interface
The data described above may be accessed or programmed by using Syscon the system terminal software.

Regional Control processor

The Regional Control Processor is one of two elements required to carry out the routing of data and speech in a Fylde multi site MPT1327 trunked system. In this context we define a multi-site system as a system having between 2 and 10 sites and which enables mobile to roam between these sites. The RCP controls inter-site communication and links to and from the PSTN/PABX via the Fylde PCM switch

Providing an aesthetic match to the rest of the Fylde product line, the latest RCP technology is housed in a slim line 2U, 19" rack mounted case. As with all Fylde products, the unit is fully compatible with current European emission and radiation specifications (EN50081-1 and EN5022).

Connections to the RCP
- Inter-site links are established via standard connections of between 2400 and 19200 Baud full Duplex from the SCI at each site.

If interconnection between more than 10 sites are required, then the RCP also provides a gateway to the Fylde Inter-Regional Processor. This then allows up to 16 RCPs to be inter-connected in an extra wide area network.

The RCP provides routing and set-up of all inter-site calls including message handling despatchers, PABX, PSTN and inter-regional connections.

The RCP also provides a temporary store for billing data, control parameters, pooled channel data and the call diversion table. This data is held in 2Mbytes of battery backed RAM (fitted as standard).

All connections to the RCP are via 9-way D-type sockets. These include -

10 sites

24 PABX lines

24 PSTN lines

2 system terminals

1 inter-regional processor

16 message handling despatchers

PCM switch

The Fylde PCM Switch is a fully BABT approved audio switch for use in the MPT1327 trunked infra-structure and patches lines to enable the multi-site audio paths to be realised. In being able to offer such a product, Fylde are able to supply all the digital elements of the complete system.

Where the RCP is, effectively, a data switch, the PCM Switch is an audio switch. However, the PCM is in essence a dumb switch and will not operate in a trunking environment without control (via an RS232 cable) from the RCP.  

For a complete central node, the 6U high version of the switch (shown above) allows upto 16 four-port cards to be fitted.

The PCM Switch provides routing to the PABX and PSTN gateways. Fylde's modular construction allows the switch to be expanded as the system grows in size, the smallest configuration being a single card offering 4 PCM Ports. In its maximum configuration, the switch can offer 192 non-blocking ports.

A 6U switch is supplied with framework as shown, power supplies and a number of 4-port cards depending on the number of ports required in the system. Each card is capable of operating individually and receives its patching instructions from the RCP via a standard RS232 connection.

The Four-Port Card
Each card provides four audio ports via an industry standard JT45 socket and is supplied complete with all barriers and interfaces to allow a variety of options, simplifying ordering and allowing users to re-configure the system at any time. There are two ports available for PABX or PSTN connection on each card.

The Switch (SSTAK)
A smaller 2U version of the switch is incorporated into the SSTAK which allows telephone interconnect on a single site.

Connections types to the PCM Switch -

PSTN or PABX
2-wire or 4-wire
E&M
Loop Disconnect (US Standard)
Ground Start (US Standard)

The SSTAK or 'Single Site Telephone Interconnect Adaptor Kit' allows inter-connection to the PABX/PSTN telephone network from a single site.

Effectively, these two units are a reduced version of the Central Node. Instead of a 6U PCM Switch card frame able to hold upto 16 four-port cards, the SSTAK includes a 2U high frame housing a single four-port card.

Instead of a RCP allowing interconnect for up to 10 separate trunked sites, a Single Site Interconnect Unit allows the connection of the following -

The above combine to make a very cost effective interconnect (about one tenth the cost of a full central node).
Beware - using a SSTAK cannot be upgraded to operate as a central node for a multi-site system. If you have any plans to upgrade to multi-site at any stage, we would urge you to consider a full central node for your single site. This will then prevent you from being left with redundant hardware when you reach the time to upgrade.

SYSCON is the Fylde Trunked Terminal System Control program and runs on a PC operating under Windows NT. The basic package is used to control between 1 and 10 sites of Fylde trunking.

A remarkable level of system control can be achieved using this software package. For a brief description we will limit ourselves to an overview of some of the more useful ones.

Mobile Validation
Mobiles can be allowed onto the system with different access levels -

Control Parameters
System operators have the ability to define up to 16 'palettes' of control parameters which can be set to automatically switch over through 16 different periods each day and through the seven days of the week.

Each 'palette' can define a different level of system loading. For example, set the system to allow short call times and improved queuing facilities, while disallowing features heavy on system resource during the busy hours. Equally, long call times and all system features can be made available for the night users.

Some of the parameters that can automatically change-over -

Channel Configuration
It is possible to use SYSCON to change the configurations on traffic or control channels in a live system. For example if interference at the site is disrupting communications on a traffic channel, that channel may be inhibited until an engineer can reach the site. This feature can be used to prevent local calls being made on a particular inter-site channel which will have the effect of improving the grade of service for inter-site calls.

Trunked overview

The contents of this page are thanks to Fylde Micro Systems Ltd. Please visit their web site.

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mike@mwc.co.uk

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Last modified: February 09, 2006