Public Safety Blog Series: Differences between a Converged and Discrete Public Safety and Commercial DAS

September 10, 2015

With the growing demand for in-building wireless, enterprises are feeling the pressure to have reliable wireless coverage and capacity in their venue for their users. To provide this, often times a Distributed Antenna System (DAS) is deployed.

Frequently, enterprises also want to ensure that first responders like firemen, police and other emergency personnel have access to communicate clearly to each other within the building or facility. Especially now that regulatory bodies and government ordinances have been implementing new requirements for new buildings or those undergoing major renovation to pass these new public safety measures.

This presents a new question: Should buildings converge both public safety and commercial cellular networks, or should they be on separate systems?

Both options are viable – Public safety and commercial DAS can be integrated if necessary, as well as keeping the two separate.  However, you must determine which option is most suitable for your current needs and future requirements.

Here are some things that you should consider:

Public safety and commercial DAS have varying goals. Commercial DAS aims to please users on their mobile devices – focusing on allocating coverage as well as capacity to accommodate the growing number of mobile users. With public safety, emergency personnel have a vital need for accessibility to communicate at all times – even in thick walled stairwells or in underground parking. Keeping the public safe is their responsibility, therefore, having the ability to communicate is an absolute necessity.

Requirements and design for public safety and commercial DAS also differ greatly. There are specific frequencies that are used when providing public safety which are different than the ones used in a commercial DAS environment. This impacts the antenna placement. With commercial DAS focusing on capacity, re-sectorization is frequently needed to accommodate traffic growth in particular areas at different times – Whereas a public safety system relies on coverage at all times, everywhere throughout the facility.

Even with varying goals, requirements and design, both public safety and commercial can be on the same system, fiber, coaxial cabling and antenna infrastructure. Integrating both the public safety and the commercial frequency bands in a single infrastructure is possible with an all-digital DAS.

In the instance where security and redundancy are of concern, both the commercial and public safety systems can be installed separately. However, it is recommended that both systems should be installed in parallel if feasible. This would be beneficial as laying both cable systems at the same time would reduce ceiling and riser work, providing cost savings.

As mentioned, public safety and commercial systems can either be converged or remain as separate systems. It depends on the goals, requirements and budget of the enterprise. For a more in-depth discussion, please register for our upcoming webinar on Public Safety Coverage Today & Impact of LTE, taking place on September 24th, 2015.

Stay tune for next week’s public safety blog as we discuss the public safety requirements of Dallas Fort Worth International Airport (DFW Airport) and how digital DAS was able to satisfy all requirements.

Share any comments or questions by tweeting us @DaliWireless. To read our past blog entries, click here.

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