FREE e-Newsletter
Important News - Hot Topics
Get them Now!
Brian Cain

Brian Cain

Brian Cain is a sergeant with the Holly Springs (Ga.) Police Department, and is known as the "Millennial cop" on Twitter. He has been in law enforcement since 2000. He hosts and produces a podcast for Millennials in law enforcement.



Michael Bostic

Michael Bostic

Mike Bostic, of Raytheon Corp.'s Civil Communication Solutions group, specializes in open architecture, systems integration of communications and data programs. Mike spent 34 years with the LAPD. He managed IT and facility development, as well as the SWAT Board of Inquiry, which developed new command-and-control systems.
Technology

Maximizing P25 Spectrum

New advancement to P25 Phase 2 technology improves interoperability in a cost-efficient manner.

February 15, 2013  |  by Michael Bostic - Also by this author

Enhanced Dynamic Dual Mode provides users with improved interoperability and increased voice capacity on P25 systems. Photo courtesy of Harris.
Enhanced Dynamic Dual Mode provides users with improved interoperability and increased voice capacity on P25 systems. Photo courtesy of Harris.

The APCO Project 25 (P25) Phase 2 standard is now ready for critical communications users. This further advancement of P25 was intended to improve upon the digital public safety radio communications standards used by first-responders, homeland security, emergency response professionals, and other agencies.

A natural progression from Phase 1 standards, P25 Phase 2 creates improved spectrum efficiency through two-slot Time Division Multiple Access (TDMA) technology. It enables multiple transmissions over the same channel for better use of limited spectrum resources. In many large systems with a high number of subscribers, P25 Phase 2 can boost spectral efficiency of the system without any compromise of coverage or functionality.   

As new and advanced as it is, many communications companies are taking basic elements of the Phase 2 standard and improving upon them. For instance, Harris engineers have expanded the capability of the standard Dynamic Dual Mode (DDM) technology that it uses in its P25 products. (Standard Dynanic Dual Mode (DDM) allows Phase 1 and Phase 2 users to interoperate in a mixed mode by "downgrading" the Phase 2 user to a phase 1 capability.)

Calling it Enhanced Dynamic Dual Mode (EDDM), the upgraded technology ensures efficient use of available channel resources. It provides users with improved interoperability and increased voice capacity on P25 systems using a mix of Phase 1 and Phase 2 radios.

Additionally, EDDM offers a cost-efficient, manageable, seamless, flexible migration path to P25 Phase 2 operation that supports an agency's own pace, budget, and frequency availability. It does this while still taking advantage of the latest technology to deliver an optimal grade of service to meet the most demanding situations. In today's economic climate, that is good news for any financially strapped department.

In improving DDM, EDDM provides several key advantages by actively determining the most effective path to process calls to maximize capacity. Rather than defaulting to the lowest common mode of operation across the entire system, EDDM actively analyzes the most effective mode of operation and allows for Phase 1 calls on one site to interoperate with Phase 2 calls on a different site, while utilizing the most capable P25 technology at each specific site.

The following example of a wide-area call placed by a Phase 2 unit on a Phase 2-only site shows how each participating site can use a different mode of operation, based on the capability of that site and the subscribing units.

With EDDM technology, transmissions made on a P25 Phase 1 site—using Phase 1 radios—will be Phase 1 calls. If the call includes another site that is Phase 2 and Phase 2 radios are participating, the system provides a Phase 2 call to that site. However, if a mixed-mode site that supports both Phase 1 and Phase 2 modes has only Phase 2 radios participating in the call, the system provides a Phase 2 call on that site, thereby maximizing channel efficiency and increasing overall system capacity. EDDM ensures automatic interoperability between P25 Phase 1 and Phase 2 technologies to deliver increased capacity for emergency, group, individual, encrypted, or ISSI calls.

I am heartened by the advances continually made in interoperable communications that not only make the jobs of first responders, emergency crews, law enforcement agencies and the like easier, but also afford them increased protection and information. I look forward to even more changes in the months ahead.

Tags: Interoperability, First Responders, Communications, P25


Be the first to comment on this story





POLICE Magazine does not tolerate comments that include profanity, personal attacks or antisocial behavior (such as "spamming" or "trolling"). This and other inappropriate content or material will be removed. We reserve the right to block any user who violates this, including removing all content posted by that user.

Other Recent Blog Posts

Just What the Hell Are We Protecting?
I do wonder to what extent the federal employees among our ranks ask themselves whether or...
Remarkable Statistics on Officer Response to Active Shooter Incidents
The author reviews the PERF report on police response and results from 84 active shooter...

Get Your FREE Trial Issue and Win a Gift! Subscribe Today!
Yes! Please rush me my FREE TRIAL ISSUE of POLICE magazine and FREE Officer Survival Guide with tips and tactics to help me safely get out of 10 different situations.

Just fill in the form to the right and click the button to receive your FREE Trial Issue.

If POLICE does not satisfy you, just write "cancel" on the invoice and send it back. You'll pay nothing, and the FREE issue is yours to keep. If you enjoy POLICE, pay only $25 for a full one-year subscription (12 issues in all). Enjoy a savings of over 60% off the cover price!

Offer valid in US only. Outside U.S., click here.
It's easy! Just fill in the form below and click the red button to receive your FREE Trial Issue.
First Name:
Last Name:
Rank:
Agency:
Address:
City:
State:
  
Zip Code:
 
Country:
We respect your privacy. Please let us know if the address provided is your home, as your RANK / AGENCY will not be included on the mailing label.
E-mail Address:

Police Magazine