Case Study: Michigan Public Safety Communications Stystem
Submitted by the APCO Broadband Committee
As FirstNet contemplates the many complexities and challenges associated with deploying a public safety wireless communications network, it will be critical for FirstNet to examine the current landscape of public safety network operators and their experiences, challenges and lessons learned. The following case study highlights some of those examples.
The Michigan Public Safety Communications System (MPSCS) is one of the largest public safety communications networks in the world, and was the first to deploy standards-based Project 25 trunked operation. MPSCS was also the first entity in the U.S. to deploy a packet-based, P25 infrastructure.
Today, the system supports 11 million PTTs per year, and has grown from 180 to 244 tower sites, covering 57,000 square miles of the state of Michigan’s land mass. The system has exploded in size and support since its early days as a system dedicated to the Michigan State Police. Since initial deployment, the system has grown from 8000 to 64,400 public safety users, from 180 to 244 tower sites and from 153 to more than 1,413 agencies.
To support and sustain the network, MPSCS uses a variety of funding mechanisms including annual subscriber fees. The fees are required of agencies and users unless they are used by state agencies or are for emergency management purposes. These are on a subscriber basis and are tiered by the number of talkgroups provided by the system. Some additional details of the existing MPSCS rate structures are provided below:
MPSCS uses annual subscriber fees in tiered structure, roughly:
- $200/yr, unlimited TalkGroups (TGs)
- $150/yr, (16) TGs + base statewide/interop TGs
- $50/yr, (8) TGs + base statewide/interop TGs
- $0/yr, emergency management only template
- Subscriber fees are paid by local, federal, private and tribal agencies
- State agencies do NOT pay fees.
MPSCS leverages a “credit” system driven by legal integration agreements that credit user agencies who want to join the network and have local assets and resources to contribute. This approach, which helped inspire the proposal presented in this document, accomplishes some important objectives.
- Provides MPSCS with assets and resources which MPSCS probably could not otherwise afford
- Allows user agencies to expand, supplement and design their network to meet their specific needs
- A common scenario is the deployment of a simulcast subsystem that provides more robust indoor coverage than is provided by the mobile designed MPSCS baseline coverage design. This approach is being used by more than seven counties in the State.
- Allows user agencies to offset costs
- Potentially creates incentives for user agencies to offer resources. Since resources are integrated into the network, they become operational assets for other users in the state.
MPSCS – City of Detroit Integration
In 2002, the City of Detroit strongly desired its own public safety radio system, but in examining the costs and complexities of the plan, it began exploring the possibility of integrating into the existing statewide MPSCS. As the design proceeded, it became clear that the additional sites and the portable, in-building coverage required by city of Detroit operations exceeded the backbone design of network at that time.
The decision was made that the city of Detroit would supplement the MPSCS by deploying a new zone. This approach provided some distinct advantages:
- Added an additional zone to system (the 7th)
- Allowed Detroit to “divorce” from MPSCS someday, if necessary
- Added coverage for MPSCS users
- Expanded footprint to statewide for Detroit users
- Agreement credited city at 50% of infrastructure value against subscriber fees
- All infrastructure included
- Towers, generators, repeaters, microwave
- Time bound at 10 years
- Agency pays no subscriber fee until credits expire (either by consumption or timeframe expiration)
The MPSCS has 23 similar integrations into the larger network, most notably large county simulcast systems that deliver enhanced in-building coverage and operational capabilities to public safety users in their counties. The simulcast subsystems or additional multicast sites provide additional coverage and capacity, and by partnering with MPSCS, this program has been highly successful overall. In the 15 years of operation, MPSCS has encountered some challenges that may be useful to outline here:
- Achieving local “buy-in” and trust from local agencies to participate in the statewide system is a common and ongoing challenge.
- Once the agreement expires and annual subscriber fees are required, MPSCS has had a constant and expensive challenge of instituting billing and getting agencies to pay for the services provided, since these expenses are often not proactively captured in planning budgets.
- Turning off the network operation is politically awkward and not always a viable option.
- Covering the increasing overall system lifecycle costs is an enormous challenge, especially as the scope and scale of the MPSCS network has dramatically expanded as described above.
- Similarly, the governance of the network has had to continuously evolve to match the increase in the number of users, the types of users and the complexity of integration agreements.