KAIROS based DMR Simulcast & Tier 3 Trunking Solutions



Multi-Frequency & Simulcast Radio Systems


In Multi-Frequency (multi-site) systems, where different frequencies are required at each radio site, the handover (site coverage changing) and roaming (research of desired group of users) is relatively slow and users will typically have to change channels or use a beacon function as they move between sites.


A Simulcast network allows all repeaters synchronise their transmissions in time, effectively creating a large single cell which significantly reduces the time required for transmissions to reach a radio terminal or to locate the correct base station. Radios connected to a Simulcast network can move from one location to another without the need for the user to change channels; simulcast is extremely user-friendly.



► Relatively frequency inefficient
► Good use of ‘spare’ channels
► Good mobile coverage
► Low number of talk-paths required at each site
► Reduced co-channel interference from multiple sites


► Frequency efficient
► Greater coverage with overlap
► Improved in-buildings coverage
► Easily expanded without reprogramming radios
► Additional sites can be added without a requirement for
new frequencies or any terminal changes


DMR Tier 2 simulcast offers increased range while DMR Tier 3 offers large capacity wide area


Simulcast network highlights


► No complex setup required, Kairos automatically manages the complex configuration and timing needed for any size of simulcast system making setup much easier


► Using the same RF channel over the whole coverage to give a “large single cell”


► Communications can be both on open and on selective channels, with semi-duplex mode between mobile terminals or duplex mode between Repeaters


► The network makes the automatic selection of accessing terminals and will broadcast the signal on the same frequency throughout the coverage area


► The terminals are served regardless of their position as if they were covered by a single repeater


► Improved coverage in existing ‘dead spots’ with little degradation in overlap areas


► Improved building penetration for portables


► The network is “transparent” to the signalling terminals (5 tone/ FFSK selective call, DMR selective call and messages etc)


► Analogue, DMR Tier 2 and DMR Tier 3 trunking are all supported


A KAIROS based DMR Tier 2 solution using Kenwood DMR hand-portable and mobile radios including the NX-5000 and NX-3000 Series equipment can be configured for both Multi-Frequency and Simulcast operation and supports multi-protocol (analogue/digital) functionality, IP-connected or conventional dispatcher and phone patching and SIP telephony.



KAIROS System Configurations


Dual Timeslots Fixed Station/Repeater

KAIROS can manage two DMR timeslots, using a single antenna. For a dispatching operation, it can be configured to provide access to an external radio network, alternatively, by adding a duplexer, KAIROS can be configured as a standalone repeater.


Kairos Dual Timeslots fixed station - Repeater


Analogue and DMR Tier 2 Simulcast or Multi-Frequency IP-linked Base Station

KAIROS supports IP connections between base stations to achieve multi-site hierarchical systems. The role of a device can be set as Master, Secondary Master, Slave or Backup Master. A Master manages up to 32 Slaves/Secondary Masters, secondary masters can in turn control up to 32 slaves. Creating small or very large resilient networks is a simplicity itself with this architecture.

Kairos Analogue & DMR Tier 2


Analogue and DMR Tier 2 Simulcast or Multi-Frequency RF-linked Base Station

KAIROS can be configured as a “LAN extender” supporting the RF narrowband connection between different sites. It is the perfect solution when the connecting distance is large, or when the radio link path is not in line of sight.

Kairos DMR


Single site DMR TIER 3 Trunked System

With a built-in SW Agent Tier 3 Controller, channels can be efficiently shared among all users, typically with no additional hardware in small and medium size systems. For larger or more complex systems, an external Trunking System Controller (TSC) needs to be added only to large and complex networks.

Single site DMR TIER 3 Trunked System


Multisite Simulcast or Multi-Frequency DMR TIER 3 Trunked System

A DMR Tier 3 controller can manage a group of IP-linked networks to enable a multi-site, multi-carrier (Simulcast or Multi-Frequency) system.

Multisite Simulcast


Built-in Signalling & Protocols


Signalling & Protocols for Kairos



DMR Kairos Spec chart


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Radio Activity case studies