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Selex PRR   H4855
Personal Role Radio

The H-4855 is a short range Personal Role Radio (PRR) developed by Selex Communications 1 in the UK in 1999 and introduced for world-wide military use in 2002. The radio is used by Special Forces (SF), reconnaissance squads and infantry sections for direct tactical soldier-to-soldier communication. Although the radios are not protected by means of voice encryption, they are classed as LPI (Low Probability of Intercept) and LPD (Lower Probability of Detection) devices. In the US, the H-4855 PRR is known as AN/PRC-343 2 and as Integrated Intra-Squad Radio (IISR).

The radio operates in the 2.4 GHz band and uses spread spectrum technology. It weights 1.5 kg and is powered by two 1.5V AA-size penlight batteries, allowing 20 hours of continuous use.

Being a low-power device it has a range of just 500 metres, but works well through the thick walls of a building. The PRR is used by all British Forces, some US forces and even by UN peace keeping forces. The device is typically issued to every member of an eight-person infantry section. A separate wireless Push-To-Talk (PTT) unit with a 2m range is available as an option.
H4855 Personal Role Radio with headset

The H4855 PRR was originally developed for the UK's Bowman Integrated Communications System but was spun off in 1999 so that it could be implemented more quickly. The first 45,000 units entered service in 2002 and although they are not compatible with the rest of the Bowman system 3 , they have revolutionised intra-squad communications and small-unit tactics [2]. The standard PRR was succeeded in 2005 [3] by the Enhanced & Encrypted Personal Role Radio or EZPRR which provides AES128 encryption and enables secure voice and data communications.

  1. The H4855 was originally developed by Selenia Communications, which was later renamed to Marconi-Selenia Communications and is now known as Selex ES [2]. Some devices are still labelled Marconi. On 28 April 2016, Selex ES was renamed Leonardo, after its parent company.
  2. AN/PRC-343 is also known as NSN 5820-99-721-8335.
  3. Although the spread spectrum technology used for the PRR is not compatible with other Bowman equipment, a dual-role option is available to allow the PRR to control an external Bowman transceiver without swapping the headset. Such units have two PTT buttons on the side panel.

H4855 Personal Role Radio with headset H4855 Personal Role Radio H4855 Personal Role Radio with headset H4855 Personal Role Radio with headset Headset Disconnected side-assembly H4855 Personal Role Radio with headset H4855 PRR in pounch

The PRR is extremely easy to operate. Once the headset is connected, it is switched ON by setting the volume dial to the first (non-zero) setting. The radio responds by sounding 3 short beeps through the headset. When the radio is turned OFF, it produces 5 longer beeps in the headset.

The volume can be controlled in 5 steps. Each step produces an acoustic feedback (beep) via the headset. The radio has 256 channels, 16 of which can be selected directly via the channel selector (next to the volume control). Selecting a channel also produces an acoustic feedback. The transmitter is activated with the Push-To-Talk switch (PTT) at the right side. Alternatively, the transmitter can be operated by means of an optional remote control unit with a range of 2m.

At the bottom left is the battery compartment which accepts two 1.5V AA-size (penlight) batteries. Commonly available (commercial) batteries are used for this radio in order to avoid supply problems. The section at the right (holding the PTT) can be removed as shown here:

The reason for removing the assembly at the right is twofold: (1) it provides access to a 16-position channel selector (giving a total of 16 x 16 = 256) channels, and (2) it can be swapped of a Dual-PTT unit, which can be used to simultaneously operate a Bowman Combat Net Radio from the same headset. In the latter case, the empty area below the PTT holds the second PTT.

The following accessories are available for the Personal Role Radio:

Headset Remote control unit Disconnected side-assembly
H4855 Personal Role Radio with headset

A simple lightweight headset is supplied with every PRR. It has a very short cable and connects directly to the headset socket on the PRR.

The headset consists of a single earpiece with an adjustable gooseneck noise-cancelling microphone mounted at the bottom. Elastic straps are used to fixate the headset on the operator's head. At the end of the short cable is a black LEMO connector that mates with the headset socket on the PRR.

Remote PTT
A wireless remote PTT is available as an option. In combat situations it allows the radio without leaving a hand from the rifle. It can be carried on the wrist but also on the weapon.

The remote PTT has a range of 2m and it powered by an internal 3.6V Lithium battery. It operates at 433 MHz and must be paired with the radio before it can be used [4].
Remote control unit

Dual PTT
The assembly that holds the PTT and the headset socket, at the right side of the radio, can be replaced by a Dual-PTT variant. This allows a second radio (e.g. a Bowman Combat Net) to be operated from the same headset.

The existing assembly can be removed by loosening the locking bolt at the right, towards the bottom of the case, as showm in the image on the right.
Disconnected side-assembly

The radio is normally held in a canvas or nylon carrying pounch, such as the one shown in the image on he right. It protects the radio against dirt and allows it to be attached to the uniform or webbing.

In order to obtain the maximum range, the radio should be carried as high as possible, preferably on the webbing behind the left shoulder. This is why the headset cable is so short.
H4855 Personal Role Radio with headset

Headset Disconnected side-assembly H4855 Personal Role Radio with headset H4855 PRR in pounch Remote control unit Remote operating the PTT

The PRR has only one socket for connection of ancillaries. In addition, it is possible to connect a standard Bowman (or other) military radio set by using the appropriate Dual PTT switch pack option. The connections given below are defined as 'when looking into the sockets'.

Headset socket
  1. Microphone (in)
  2. PTT
  3. Speaker (out)
  4. GND (speaker)
  5. GND (mic)
Switch pack connector
The pinout of the internal switch pack connector at the right side of the radio is based on information found on the internet, mainly from Brooke Clarke [4], and is subject to change. If you have additional information, please contact us.

  1. MIC
  2. ?
  3. SPK
    Speaker (out)
  4. V
    3V (out)
  5. GND
  6. PTT
  7. ?
    busy pips
  8. ?
  9. ?
  10. RX
    Data in
  11. TX
    Data out
  12. ?
Headset wiring
Base on the pinout of the 5-pin LEMO socket given above, a suitable headset or microphone/speaker combination with Push-To-Talk (PTT), should be wired as shown in the diagram on the right. The pinout of the LEMO socket is given when looking into the socket on top of the radio.   

    Enhanced and Ecrypted Personal Role Radio
  • LPD
    Low Probability of Detection
  • LPI
    Low Probability of Intercept
  • PRR
    Personal Role Radio
  • PTT
    Push To Talk
  • SF
    Special Forces
  1. Selex ES Ltd, PRR Datasheet
    2013. Retrieved May 2015.

  2. Wikipedia, Personal Role Radio
    Retrieved May 2015.

  3. Business Wire, Next Generation Personal Role Radios from Selex Communications
    4 October 2005. Retrieved May 2015.

  4. Brooke Clarke, Bowman H4855 AN/PRC-43 Personal Role Radio
    Retrieved May 2015.

  5. Military Radio Specifications, AN/PRC-343 aka H4855 aka PRR
    Retrieved May 2015.
Further information
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Crypto Museum. Created: Monday 11 May 2015. Last changed: Wednesday, 05 October 2016 - 04:43 CET.
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