Using the internet to get the message across - Part II

Last issue we introduced RoIP as a means to achieving interoperability in and across two-radio networks. Interoperability is more than the integration of different radio formats and RF interfaces.

Interoperability is the deliverance of services across divergent radio networks, in other words, it is the transparent delivery of services to radio users, operators and, equally, those requiring the services delivered by the radio users.

It is indeed important that we retain that in the forefront of our thinking.

Simply put, the casualty needing an ambulance, the firefighter needing back up, the maintenance crew awaiting a spare, none of these care very much about how they get the information they need.

It is imperative that we keep the needs, objectives and constraints of the users in mind when deliberating on how, when and to what extent we implement a technology or practice.

Technology, and indeed standards, are a means to an end and need to be viewed in that context.

In two-way radio, we have a large installed base of radios and networks across geographies, with varying formats, frequency allocations, capabilities and capacities: HF, VHF and UHF; analog; digital and trunked, private and public use; open, restricted and secure.

Suffice to say the limited radio spectrum is full of disparate networks sharing the same resource. It makes sense to retain the available capabilities and overcome the constraints that inhibit interoperation.

Clearly, these constraints are primarily dictated by the installed radios and their formats, and secondarily by the type of operation and its dispatch command and control structures.

All this applies to the case we are looking at here.

It is prudent that we look at the radio side first. Broadly speaking, radios differ in frequency and analog or digital format. Further characteristics are functionality and feature set. It makes sense to isolate these constraints to the radio itself.

This removes the hurdles to interoperability from the network and places it where it belongs, the radio interface.

The most straightforward way to make these radios interoperable is to connect them to a RoIP backbone (see part I, Figure 2). A simple and modular RoIP interface that is deployed with the radio and enables it to send and receive baseband and control data as IP conform data.

This combination ‘IP-Radio’ has an IP address and hence is now simply a node on an IP network, with radio capability.

On the command and control side, platforms and applications are typically tailored to the network and its distinct operations. Here it is imperative that we provide the operator with the opportunity and means to upgrade, redesign and integrate befitting needs and objectives, budget and schedule.

Again, the open and modular structure of a node-based RoIP backbone provides all options and allows operators to execute a soft migration.

The structured, modular RoIP backbone has individual nodes deployed where they are needed. The radio network can link these nodes through a central application (command and control) and/or link individual nodes.

Such a structure is readily tailored to any target operation, is flexible, resilient to change and inherently ‘evolvable’: nodes (IP-enabled radios) can be added as needed, upgrades and improvements to the command and control application can be implemented concurrent to ongoing operations.

When implemented appropriately, nodes can be chosen from any vendor. Returns are achieved earlier, basically from each stage of implementation.

Last but not least, this ‘soft migration’ provides excellent knowledge transfer and cost effectively develops competence.

In the case discussed here, a first trial implementation is required. The trial allows the operator to assess such parameters as coverage, IP capacity and voice quality and usability, all of particular concern in the client’s fairly extreme geographical environment.

In its simplest form, this trial sees a few IP-enabled base stations, realised by ‘pairing’ RoIP-interface-unit (RIU) and radio (base station).

Figure 1: Stage 1 of RoIP migration.

Figure 2: Network integration.

The counterpart to the RIU/radio (‘RoIP-radio’) is a ‘soft console’. This, in its simplest form, is an application on a PC that takes the IP-packet data from the IP-enabled radio, represents the radio and control functions on the screen and reproduces the audio using the PC’s soundcard.

The functionality of the soft console is basically only limited by the functions built in. A soft console is easily expandable via SW upgrades.

Further radio sites are integrated by simply adding an RIU to the radio to be integrated. Additional functions are provided by adding features to the RIU, eg, a virtual control head.

Figure 3: Adding RoIP network functionality and features.

On the command and control side, other features are added to the soft console, eg, to display and use the remote control head, crosspatch two remote radios, send group messages or connect to a cellular or PSTN network.

Aside from adding more IP-enabled radios, network expansion is largely a matter of managing the IP network capacity. The RoIP network supports integration with other devices and formats such as external PSTN and cellular and VoIP with SIP (session-initiation-protocol).

Security and network reliability can use applications and developments from the IP world, simplifying their implementation.

Network operation and maintenance become more efficient as well, eg, allowing more advanced remote monitoring and troubleshooting as well as mobile administration using, eg, public internet access.

Enhancements, extensions and upgrades, even custom applications can be readily and easily added, without substantial changes to the platform, often simply from a central location, or indeed, remotely via the internet.

Typically, there is no need to upgrade HW on site.

Last, but not least, such a structured RoIP-based network can accept radios with enhanced technology, such as integrated IP interfaces, new formats and, indeed, non-radio hardware, software and functions.

A RoIP network repeater/server with SIP capability is added to support further network expansion. The repeater handles the transport to and from all remote radios and their respective RIUs. It manages the TCP/UDP protocols and routing, essentially making all remote radio/RIUs appear as local units.

Multiple operators from different locations can then access individual radios without the need to configure individual patches, routings, etc.

An additional benefit is that the traffic load on the (WAN) network is optimised, creating higher efficiencies on existing infrastructure.

The SIP application allows the repeater to integrate with IP-based (VoIP) phone systems using session-initiation protocol (SIP).

This enables features such as virtual phone lines at operator consoles and automated routing of phone calls across IP and radio network.

In the ensuing phase, more network functionality and coverage is added to the network. More radios will be IP enabled and patches and group functions, PSTN, VoIP and cellular interconnects and logistic/command structures are implemented and configured for designated areas and functions as needed.

Mobile sub-command units are integrated and maintenance centres and technicians supplied with appropriate RoIP-based SW consoles.

Network monitoring and resource allocation is enhanced by enabling ad-hoc network extensions and dynamic routing and integration with non-radio telecommunications infrastructure.

This RoIP-enabled land mobile radio network provides a ‘futureproof platform’. Network operators can readily and functionality and network elements beyond the fundamental radio features and capabilities:

• Better use of new and coming technologies in radio communications, such as special data messages, data transport, etc;
• Adding new features such as global positioning, logging functions and command and control features;
• Integration of internet (IP) applications and services;
• Better use of radio infrastructure and assets, eg, remote sensors, video-capture and data-gathering devices, interconnected via RF link to a RoIP-enabled station;
• Surveillance and monitoring in rural and remote areas, eg, for infrastructure and security assets;
• Temporary deployment of fully functional subnets, eg, for major construction projects;
• Government and defence applications on the RoIP backbone;
• Integration with aviation and search and rescue services;
• Deployment of custom RoIP applications and equipment, eg, in designated ‘RF-free’ zones.

The list is long and the possibilities vast. The only limitations are truly with the radio interface and its elements - if it can connect to the RoIP backbone, it can connect to anywhere in the world, anytime.