Digital Mobile Radio

Advanced base stations for the new generation of

professional mobile radio

Via Ponte Nuovo, 8 - 20128 Milano — Italy

Tel. +39.02.36514205 - FAX/Voicebox +39.1782242408

radio.activity@fastwebnet.it - www.radioactivity-tlc.com

About Radio ActivityAbout Radio Activity Radio Activity S.r.l. is a young and dynamic

electronic engineering company with its

operational headquarters in Milan.

The company carries out design and pro-

duction of wired and wireless equipment

and systems for telecommunications net-

works in the professional market.

The engineering team to whom the Re-

search and Development is entrusted is

composed of engineers who have com-

pleted more than 20 years of experience in

this field at major telecommunications

companies.

The deep expertise in the design and im-

plementation of radio frequency hardware

and complete mastery of techniques for

programming DSP devices (Digital Signal

Processing), allow us to tackle complex

projects and offer customized solutions to

the real needs of the Customer.

The solutions identified are the result of

intense work by top-level professionals

with multidisciplinary skills, which skillfufly

integrate products and technology.

Radio Activity has advanced techniques,

for the establishment of analog and digital

simulcast radio networks and numerous

products for data transmission and cen-

tralization of communications via digital

audio matrices based on DSP.

In order to maintain the structure lean and

focused on its core business, all production

activities are entrusted to factories spe-

cializing in the assembly of electronic cir-

cuit boards and mechanical assembly.

Only strategic assets are maintained inside

with high quality levels. Besides of course

hardware and software design, we control

the choice of valuable components and

final testing of equipment and network.

This will guarantee the continuous updat-

ing of the used components and total

quality control of external processes.

DMR: an open ETSI standard DMR standard (ETSI TS 102 361/2/3) has been defined in ETSI envi-

ronment, by a working group composed by main PMR equipment

manufacturers worldwide.

Digital Mobile Radio is able to give “added value” to current analog

systems and at the same time it grants a gradual migration between

the two technologies, safeguarding investments and specific exist-

ing operational requirements.

DMR system can coexist with conventional analog systems on adja-

cent channels, without any performance loss of each of systems.

Frequency modulation has constant envelope (unlike the TETRA

which do not have a constant envelope).

Transmitters are very similar to their traditional analog version, be-

cause expensive linearization techniques are not needed: they can

work in saturation (clipping) mode (C class o superior) with very low

consumption => solar panels can be used.

The employed digital modulation is 4FSK (Four-level Frequency Shift

Audio/data channels are managed by two

timeslots sequences, working in TDMA

mode (Time Division Multiple Access), shar-

ing the same radio channel with 12,5KHz

bandwidth.

The two audio/data channel are per-

fectly separated and independent each

other, as if they were operating in a

conventional manner on different fre-

quency carriers.

Just one radio device (only 1

TX) provides 2 channels with-

out any RF coupling system

DMR overview

Key) and the information bits are transmitted in pairs, each pair

assigned to a frequency shift.

Transitions between a status and the following one (that is be-

tween a pair of bits and the following) are continue and

“smoothed” by a fil-

ter which reduces

high frequency com-

ponents.

The shape filter is a

“Raised Cosine” func-

tion.

DMR repeaters family by Radio Activity. Radio Activity has developed the DMR standard over the rugged

and largely utilized RA-XXX base stations. More then 1.400 RA-

XXX was installed in the past 2 years for emergency or essential

services applications.

The base station family RA-XXX has been designed using the lat-

est technologies in the Radio Frequencies and Digital Signal Proc-

essing fields. The transceivers are “fully digital ” developed fol-

lowing the theory of “soft radio” in which the modulation and

demodulation processes are performed by algorithms of Digital

Signal Processing (DSP) .

The radio modularity, as well as the other functions like remote

control, self test, self calibration, over temperature protection,

etc, minimizes the management and maintenance costs of the

equipment. The receiver section has excellent linearity character-

istics, which allow that more radio stations work on the same fre-

quency band.

These devices are fully programmable and easy to configure both

in Hw and SW, consequently this will provide optimum solutions

for any radio communication exigencies from a single repeater to

complex networks with tens of base stations.

Basic model already has all the characteristics to work as a dou-

ble standard repeater with all the features of analog and digital

Advantages of DMR Advantages of DMR

Over conventional systems

∞ Two contemporary communications

over 12.5KHz bandwidth

∞ European open standard

∞ Lower minister frequency license costs

per channel

∞ Increase spectral efficiency

∞ Fast and reliable data communications

∞ Smooth migration from analog systems

∞ Communication security with various

level of encryptions

∞ Powerful features (ID on PTT, emergency

call, text messages, ..)

∞ Built-in applications (positioning over

voice, telemetry, …)

∞ Easy upgradability from single repeater

to network

Over TETRA systems

∞ Very low infrastructure costs

∞ More coverage area

∞ Total reuse of existing conventional in-

frastructure (sites, power supply, ant…)

∞ Easy to manage and maintain

∞ Very low power consumption (solar

panel compatible)

∞ Low cost TCP/IP or UHF links between

the base stations

∞ Better spectral efficiency and same main

features

∞ Available in all PMR bands (70 MHz, 160

MHz, 450 MHz)

∞ Availability of simulcast solutions for low

traffic and wide area coverage systems

DMR overview

service. It can be equipped with double receiver to counteract fad-

ing effects through diversity space reception.

DMR: network solutions The Radio Activity base stations are ready to make networks ex-

pandable from single repeater to a multi-frequency or iso-

frequency multi-site system, with a lot of type of links, operating

with the most common transportation system technologies, like

microwave link, DMR UHF radio, fibre optics, copper pairs, generic

TCP/IP connections and mixed media also.

The entire radio system is designed to automatically react to fail-

ure situations and seek the configuration of minimum possible dis-

ruption (progressive degradation). The network reacts, depending

on events, re-directing the paths of the signals on the transport

network, creating sub-autonomous networks, up to turns an iso-

lated base station as a simple repeater (local bridge) up to reduce

power consumption in the over temperature events.

The precision in timing and synchronization, the high performance

digital equalization and the built-in algorithms guarantee an opti-

mal functionality even in equal field strength areas.

DMR simulcast environmental

has many advantages respect

to the analog one due to the

better C/I performance and

due to the powerful coding

applied. The result is a clear,

noise free, mobile radio net-

work in critical propagation

area also.

About SIMULCAST About SIMULCAST

A simulcast network is a very powerful

radio network in which all the repeaters

are active on the same frequency and at

the same time.

Main advantages:

∞ Automatic and continuous roaming

and hand-over => Easy to use, fast

setup call

∞ Functioning like single “big repeater”

=> automatic and simple conference

call operation

∞ All stations directly connected to the

network => Integrated communication

sys

∞ The same RF channel over all Network

=> no change of channel in the cover-

age area, frequency saving

The simulcast solution is the best in case of

emergency due to easy and fast “open

channel” mode of operation:

∞ all people involved in emergency can

listen all communications so they are

continuously informed about the criti-

cal situations

∞ the regulation of network access is

made by user, absolutely more intelli-

gent and efficient than a trunking SW

logic

All transmitters send the same information signalson the same carrier frequency

fc

fc

fc

The two received signals can be com-

bined by digital ri-phasing to obtain

the vectorial sum.

No scanning required.No scanning required.No scanning required.

Forget your previous Forget your previous Forget your previous

trouble experience on trouble experience on trouble experience on

simulcast networks.simulcast networks.simulcast networks.

DMR overview

Unique or more interesting Radio Activity features ∞ Automatic dual mode DMR/Analog operating

∞ Designed for TCP-IP simulcast applications

∞ Soft diversity receiver

∞ Full LINUX core

∞ Automatic alarm’s messages sending by the base station to

the mobile equipments

∞ Ethernet port with full traffic available (DMR audio, data

and signaling) for Operative Center applications or tele-

phone gateway

∞ Extra low ETH bandwidth (33.6kb/s) required to connect

the base stations

∞ Software remote upgradability

∞ Easy scalability from single repeater to simulcast network

∞ Built-in both digital and analog voting systems

∞ A lot of timing/synchronism mode available for simulcast

applications

∞ Powerful GSM/GPRS/TCP-IP/DMR based remote control

∞ Factory remote assistance available

∞ Multi-key encryption

∞ Very low power consumption (typ. 8 W @RX)

∞ Compact modular design

∞ 100% TX duty cycle

∞ No fans needed

Main realizationsMain realizations

∞ A “dual mode” simulcast network TCP-IP

linked in 80MHz band with 16 base sta-

tions. User: Italian motorway.

∞ 300 radio stations in 450MHz band for

fast data transmission point-to-

multipoint. User: ALBACOM.

∞ 700 radio stations in 450MHz

band for point-to-point com-

munication. User: WIND/ENEL.

∞ supply of more than 150 systems based

on IP modem RA-md1 for use with “over

the mains” communication

systems. User: ENEL Dis-

tribuzione.

∞ radio stations for point-to-

point connection. User: EDISON.

∞ simulcast radio network for emergency

radio coverage for Fire Brigades in

Lötschberg rail tunnel between Frutigen

and Raron (Switzerland): 34 km of tun-

nels with 26 simulcast radio stations

linked by multiplex.

∞ four simulcast VHF radio networks with

UHF links , Master and Sub-master base

stations, for Region Liguria.

∞ simulcast VHF radio network with mixed

connection via multiplex and “over the

mains” carrier with delays self-

calibration through the GPS signal. User:

Valais Electric Body (Switzerland).

∞ emergency radio coverage of motorway

tunnel in Amberg for ASCOM Austria.

∞ three channel emergency simulcast ra-

dio network with optical links for radio

coverage of motorway tunnel in Liguria.

∞ several simulcast radio networks with

UHF links and microwave link for data

and audio mobile communications

( Mountain Region of Campania, Alpine

Rescue in Marche Region , Aqueduct of

Romagna, Motorway and Police of Val

d'Aosta Region, Watch services of FIAT,

Commonwealth of Engelberg, ..… )

UHF links

UHF links

Slave

Slave

Master

Sub-Master

p.p.

s.

SLAVE

IP

p.p.

s.

DMR overview