In my business development role for Motorola, I often meet with customers who are challenged to keep their teams connected as their workers increasingly embrace smartphones and computers in their daily activities. Of particular interest to many Land Mobile Radio (LMR) customers is the option of using broadband push-to-talk (PTT) to drive additional value from their existing LMR networks while providing additional flexibility and mobility to workers. For most customers I know, adding the ability for smartphone and desktop users to communicate with their radio users is a no-brainer.
The ‘What’ is the easy part. ‘How’ is where many customers need guidance.
Which Option Is Right For me?
When it comes to LMR integration with broadband networks there are two key options to choose between: wireline and wireless integration. Choosing the correct radio integration method is important to ensure your communications capabilities align with your organization’s goals and needs. The following five questions will help guide your decision between using wireline or wireless radio integratio
1. Can your LMR network interface via an IP wireline connection?
It’s important to carry out an inventory of your radio systems and what networks you want to interface with. If you have an older radio network, e.g., an analog or conventional system, a wireline solution may not be available. In this instance you can still link your LMR core to broadband PTT networks but this will need to be done using a wireless interface via a donor radio. If you have a newer trunking system, typically released from 2013 onwards, then wirelineIP interfaces are likely to be available that will connect to your LMR network.
2. Do you need richer voice services?
If simple PTT is the main requirement for your users then a donor radio solution is worth considering. But in operational situations, it can be valuable to have richer services available; services offered via a wireline IP connection.
Wireline Solutions Enable: • Unified aliases and naming of users and talkgroups over LMR and broadband PTT networks• Private calls to other broadband or radio users• Call control messaging that communicates directly with the LMR network, receiving grant and deny tones to ensure the LMR network’s resources and sites are ready to take the call
Donor solutions work differently. They provide a “best effort” in sending audio to the LMR network with no feedback (audio or otherwise) to the initiator of the call that their audio was successfully transmitted across the radio network. If there is a lot of system traffic and resources are pushed, calls may be lost or users may experience partial messages.
3. How flexible do you need to be?
This question relates to your operations. Specifically, how many talkgroups do you require? And do you need them to be set up quickly? For instance, if you anticipate a need to respond to dynamic incidents, creating new talkgroups on the fly, wireline integration will better suit your needs. Using a programmable interface on your broadband PTT server, you are able to quickly and easily configure and turn on talkgroups.
With wireless interfaces, the process of setting up donor radios for each talkgroup can be time consuming: you will need to find a new radio, reconfigure it and connect it to the core and radio gateway unit. This said, with smaller networks or networks where talkgroup requirements are predictable and you just need simple PTT services, donor radios remain a strong solution.
4. How scalable do you need to be?
With wireless interfaces via a donor radio each additional talkgroup brings an associated increase in infrastructure. You will need a fixed antenna on the premises and you’ll potentially need a large number of donor radios in racks as well as monitoring and alarm equipment to oversee them. As each radio will also need its own channel you may have to carefully manage RF spectrum. It’s also important to bear in mind that each donor radio will physically need to be close to the LMR users, so you might have donor radios spread around a number of sites.
In smaller scale networks, or networks where users are not dispersed across wide areas, these considerations do not present a challenge to using donor radio integration. Even in larger networks, such challenges can be overcome with an experienced deployment team. However, if your network is more fluid and you need to add more talkgroups or connect people on LMR systems in many different areas with broadband networks then your equipment costs escalate.
With wireline integration the connection to the radio system is already made via the IP network so it’s easy to add new talkgroups between the two systems and is much more cost and time effective. In addition, there are broadband PTT servers available that can scale to support thousands of users.
5. Will Your Requirements Change?
As your organization evolves so will your service requirements. IP-based solutions provide a more versatile platform to support your changing needs. Services that include location and cross-network text messaging and notification are now being offered by some solutions. These capabilities allow you to enhance operational support and safety features while driving more value from your systems. If you have plans to invest in unified messaging or GPS tracking capabilities across LMR and broadband in the future wireline integration is a better fit for you.
Of course these are just a few of the many considerations that go into properly planning and executing a broadband PTT deployment. I’d love to talk with you in more detail about Motorola’s broadband PTT solution, WAVE, and your integration options if you’re interested.
Rob Mitchell, Director, Global WAVE Business Development