TETRA  |  2014-04-07

Traffic cops in fringe areas fumble as walkie-talkies go dead

Source: Rasheed Kappan

Inadequate towers, repeaters weaken signalen. New radio equipment will be installed soon

Regulating traffic on the chaotic, clogged roads of Bangalore’s periphery could be too daunting a task. But instead of a respite from this rambling mess, the harried traffic policemen now have a new headache: Walkie-talkies that just don’t communicate!

For decades, they had relied on these handsets for line-of-sight interaction between traffic junctions. It worked well as long as the City was within manageable limits. But in Whitefield, Electronic City and other areas far from the City centre, the handsets are increasingly going deaf. Reason: Poor connectivity to the 11 control towers located in the City proper.

In Whitefield, where waiting periods at traffic junctions could exceed 25 minutes, the “silent” walkie-talkies trigger problems of manic proportions during peak hours. Manning eight congested junctions, the overstretched policemen are forced to use GSM mobile handsets at their own cost!


“We just can’t get connected. Since we don’t have a choice, we end up using our own phones,” said a traffic sub-inspector, preferring anonymity.

An estimated 2,000 walkie-talkies are distributed among traffic police personnel across the City.

The instruments operate in four channels of different frequencies in the four main traffic police divisions. A top City police control room official explained that most of the walkie-talkies were under the master controls in Public Utility Building on MG Road and VV Towers. Adding more towers would jam the frequencies, he said.

Audible enough

A hand-held portable, bi-directional radio transceiver, the walkie-talkie works on a half-duplex channel, where only one radio transmits at a time although any number can listen.

A push-to-talk switch initiates transmission. Unlike phones, a walkie-talkie’s speaker is loud enough to be heard by the policeman and people located in his immediate vicinity.

Shortage of repeaters

Since its range is too short, any physical obstacle could seriously affect the quality of transmission. Typically, the range does not exceed the line-of-sight distance to the horizon in open areas. In built-up areas and underground, this is even less. By using repeaters located at a high point in the desired coverage area, the range could be boosted slightly. The repeater listens on one frequency and retransmits on another. By linking many repeaters, the walkie-talkie range --about five kilometres-- could be increased by a few more kilometres.

However, the City traffic police have only 22 repeaters, most of which are in dire need of replacement.

A top police Wireless unit official admitted the problem, but insisted that new equipment would be installed soon. It is learnt that prohibitive costs ruled out the police acquiring the higher frequency TETRA (Terrestrial Trunked Radio) walkie-talkies that allows the transceiver to send and receive message to more than one channel at a time.