Years of experience in radio trunking lead us from the ancient concept of “scan based” trunking system to the revolutionary and innovative concept of “Smart Parking Channel” trunking system.

This new concept improves the communication’s efficiency and enhances the trunking operation in order to achieve most valuable features, delivering to the end user higher speed for dispatch or incoming calls, faster channel acquisition, greater battery life (supported by some radios), extended channel banks into plane memory, larger quantity of channels per system or site, larger quantity of channels per bank, automatic area selection, backwards compatibility with older systems.

All the radios which are not involved into a call stay - while in stand by mode- synchronized in a temporary parking channel, and not actively scanning through many other channels. When a call from any of these radios is triggered, all the involved radios, stay in the channel while the other radios are signalled to step forward to the next available channel. This produces a faster and more efficient channel acquisition management: there is no need of a long call collect tone header through all the channels in the system, but only a single header which signals the called radios to stay and a short excluding string for the radios which are not allowed to take the call, making them jump to the next available channel.

As the radio stays in a free available channel while it is in stand by mode, parked in a ready-to-go channel and awaiting for the receiving or generate a call. When the call is triggered, the conversation will start as soon as the user press PTT (Dispatch) or ID Code + * sign (for M-M calls).

SmarTrunk Xpress radios do not need to look for a free channel to place a call request after the user try to place a call, they hit the correct channel at every call attempt.

With the traditional SmarTrunk II trunking protocol, the radio keeps scanning all the time in stand-by mode, for this reason is that power save mode cannot be enabled for the older protocol, thus, battery life is shorter.

Unlikely, SmarTrunk Xpress radios will not scan, and battery save mode can be enabled to extend the battery life period. This feature will reduce the power demand of trunked radios as well as the average operating temperature.

Note: It could be possible that not all radios support battery save mode when a SmarTrunk Logic board is placed on it.

SmarTrunk Xpress protocol manages channels memories in a different fashion than earlier protocols. All of the frequencies will be programmed into the same memory page at the radio’s programming, while the logic board’s firmware is aware of the real location of each channel each different coverage area. In this way, the user should not switch the memory bank to change to a different area.

This feature could encounter some limitations when applied to radios with up to 16 max frequencies for channels group.

Many other radios as, i.e. Motorola Commercial series, supports many more channels in a plain memory.

Due to the previous protocol is scan based, the controllers generate a call collect tone of 150ms per existent channel in the system, therefore, in order to keep the channel acquisition time low, the SmarTrunk II systems were limited to up 16 channels per system.

As SmarTrunk Xpress do not use call collect tone to find the called radios in the system, and the channel acquisition time is 350ms, independently of the quantity of channels the system may have, the protocol is able to support larger quantity of channels in a system without affecting the overall system performance

As SmarTrunk Xpress protocol is able to manage the plain memory it is also able to support more than 16 channels per bank.

The fashion in which SmarTrunk Xpress protocol handles the plain memory, allow the radios to automatically select a new area if the user loses coverage at the current one.

The SmarTrunk Xpress logic boards, can even select the area by its signal power (this feature may not be available for all the brands or models). This way, the user does not need to be aware about the real coverage of the system, as in a cell phone network, “SmarTer” radios do the job.

The new SmarTrunk Xpress protocol keeps backwards compatibility with older systems. SmarTrunk Xpress logic boards can coexist with older logic boards and controllers in a SmarTrunk II environment.

However, the overall performance of this sort of mixed system will be kept with the SmarTrunk II protocol limitations, as the older protocol is not able to resolve the parking channel operation.

SmarTrunk II features are limited in Xpress logic boards. Basic features only, as dispatch calls, individual calls, telephone calls, group calls, group switch and pre PTT caller ID, will be available in SmarTrunk Xpress logic boards.

Note: SmarTrunk Xpress controllers (ST-858) do not keep the SmarTrunk II compatibility.