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Cell Phones or Two-Way Radios for Security Use?

The Need for Security Communications


Many organizations use security officers as a part of their overall security program. These officers make routine patrols, respond to security incidents, and provide other services to employees and to the general public. For security officers to work effectively, it is essential that they have a good communications system in place. This system needs to allow security officers to be summoned when their help is needed, as well as allow communications between security officers as they carry out their daily activities.


In larger organizations, there is typically some form of central security command center that serves as the hub of the security operation. In these cases, calls for security service are typically made to the command center, which in turn dispatches a security officer to the location where needed. For example, if an employee sees someone suspicious in the parking lot, she would call the number of the security command center to report the incident. The command center would then dispatch one or more security officers to the parking lot to investigate. The command center would monitor the incident, coordinate activities between security officers, and if needed, call in outside agencies for help.


Smaller organizations may not have a security command center and may only have one security officer on site at any one time. In these cases, employees usually communicate directly with the security officer who is on duty. For example, if an employee was locked out of his office and needed access, he would contact the security officer on duty and ask him to respond to unlock the door.


Communications Options


The two most common methods of security communications used today are the cell phone and the two-way radio. In the past, pagers were also commonly used but have now been mostly replaced by cell phones.


Security managers often have difficulty in deciding which communications devices should be issued to security officers: should they issue cell phones, two-way radios, or both? Within this article, we will discuss the advantages and disadvantages of both options and provide some ideas that may be helpful when planning your security communications system.


Two-Way Radios


Two-way radio systems have been used for business, public safety, and security communications for more than fifty years. Prior to the introduction of cell phones, two-way radios were really the only option when you wanted two-way communications with someone on the go.


Two-way radios consist of two parts, a radio transmitter, and a radio receiver. These two parts are combined into a single unit known as a radio "transceiver". There are three types of radio transceivers: portable transceivers, mobile transceivers, and base station transceivers. The following is a brief description of each transceiver type:


Portable Transceivers


Portable transceivers, often called "walkie-talkies", are hand-held units that can easily be carried by the security officer. These units are battery powered and have a self-contained speaker, microphone, and antenna. External microphones and earphones can also be used.


Portable transceivers typically have a range of between one and three miles depending on power, frequency, and the type of obstructions between units. Range within concrete or steel buildings can be considerably less.


Mobile Transceivers


Mobile transceivers are larger units that are designed to be mounted in vehicles. Mobile transceivers have an external microphone that makes using the radio while driving more convenient. Mobile transceivers are powered from the the vehicle's electrical system and typically transmit at a much higher power than that used by portable transceivers. Mobile transceivers also have an external antenna that is usually mounted on the roof or trunk of the vehicle. The combination of a higher transmitting power and an external antenna gives mobile transceivers a much greater range than portable transceivers; typically five to fifteen miles depending on conditions.


Base Station Transceivers


Base station transceivers are designed to be mounted at a fixed location, such as at the security command center. Base station transceivers typically operate at high power levels and use an external antenna mounted on the roof of the building. Base station transceivers can be provided with desktop microphones and speakers that can allow use of the radio from multiple locations in the security command center.


The typical security department would probably use a combination of transceiver types; portable transceivers would be carried by security officers, mobile transceivers would be used in security patrol vehicles, and a base station transceiver would be used at the security command center.


Two-way radio systems are available in several different frequency ranges. VHF high band (130 -174 MHz) and UHF (400 - 512 MHz) are the frequencies most commonly used for security purposes. Most security organizations use conventional analog two-way radio systems, although some very large organizations may use digital or trunked radio systems.


Many campuses are so large that they exceed the limited range of a portable two-way radio transceiver. To solve this problem, radio repeaters are often used. Radio repeaters are mounted at a high-point on the campus (such as at the top of a building or water tower) and extend the range of signals by receiving and retransmitting them. A repeater mounted in a very high place (such as on a mountaintop or high-rise building) can often allow portable transceivers to cover an entire city or county.


Some buildings are so densely constructed that they block out radio signals, preventing communications through more than one or two floors. To solve this problem, distributed antenna systems can be used within the building to pickup and and distribute signals between floors. These systems often use "leaky coax" type antennas installed above the ceilings.


Many large organizations may need to use a combination of both radio repeaters and distributed antenna systems to provide reliable two-way radio system coverage throughout their entire campus.


Cell Phones


Cellular telephones ("cell phones") were first introduced about thirty-five years ago. Early cell phones were bulky and expensive and only worked in limited areas. Today, cell phones are small, convenient, relatively inexpensive and used by almost everyone from small children to senior citizens. Many of today's cell phones are "smartphones" that in addition to being used to make calls, can be used for email, text messaging, web browsing, listening to music and running application programs.


Unknown to many people, cell phones are actually a form of radio transceiver, This transceiver transmits and receives low-power radio signals to and from nearby radio stations known as "cell sites". These cell sites each cover a small geographic area and communicate with all of a given service provider's cell phones within that area. In suburban areas, each cell site may cover an area of several miles, while in dense urban areas, each cell site may cover an area of a quarter-mile or less.


All cell sites are connected to a central computer which manages communications between the cell phones and the sites. As a user travels down the road using his cell phone, the computer keeps track of the phone's location and automatically switches the cell phone to the nearest site. The computer can also adjust the phone's transmitting power so that an appropriate level of power is always used. When someone dials a cell phone number, the central computer routes the call to the the cell site nearest to where the cell phone is located and rings the phone.


Good cell phone coverage is now available in most metropolitan areas of the United States. Chances are very good that your cell phone will work almost everywhere in the outdoor areas on your campus. Indoor coverage is another matter. While cell phones usually work well in wood frame buildings, coverage can be spotty in concrete or steel frame buildings, except when standing near outside walls. Cell phone coverage in below-grade basements or underground parking garages can also be a problem.


To provide good cell phone coverage within all areas of large buildings, it is sometimes necessary to install distributed antenna systems similar to those used with two-way radio systems. These systems are usually custom engineered to meet the specific needs of the building. The cost of installing these systems is sometimes subsidized by the cell phone carrier if the organization is a significant customer.


Comparison Between Two-Way Radios and Cell Phones


Two-way radios and cell phones each have their advantages and disadvantages. Here is a brief comparison of each option:


Two-Way Radios




  • Simple and easy to use.

  • Rugged and reliable - suitable for use in outdoor and heavy industrial environments.

  • Loud audio output - suitable for use in noisy areas.

  • Available with many accessories designed specifically for security use.

  • Allows "one-to-many" communications - all officers can hear all communications. Very beneficial when many officers are involved in responding to the same security incident. Also provides officers with overall awareness of what is happening on the campus.

  • System is completely owned and operated by the organization.

  • System can continue to work during times of crisis (earthquake, tornado, etc.) that may overwhelm public cell phone network.

  • Less opportunity for misuse by security officers.

  • No ongoing fees for cell phone service or airtime.



  • Requires initial capital investment for radios, licensing and installation.

  • Must install and maintain own infrastructure (antennas, repeaters, emergency power, etc.)

  • Limited coverage - only works in designated areas. Generally can't be used away from campus.

  • No ability to make or receive telephone calls (a).

  • No ability to use for text messaging, email, or web browsing.

  • No ability to use with security monitoring applications (guard tour, remote video viewing, etc.).

  • Easy for outside parties to eavesdrop on security communications using radio scanner (b).

Cell Phones




  • Little or no initial capital investment (with 2 year service commitment)

  • No need to install and maintain infrastructure (antennas, repeaters, emergency power, etc.)

  • Wide coverage - works anywhere cell service is available.

  • Ability to make or receive calls to and from any telephone.

  • Ability to use for text messaging, email, or web browsing.

  • Ability to use with security monitoring applications (guard tour, remote video viewing, etc.).

  • Difficult for outside parties to eavesdrop on security communications using radio scanner.



  • More complicated to use.

  • Generally less rugged and reliable than radio units. May not last long in outdoor or heavy industrial environments.

  • May be difficult to use in noisy areas.

  • Few accessories designed specifically for security use are available.

  • Higher potential for misuse by security officers. Officers may make personal calls, text, or participate in social media activity while on duty.

  • Only allows "one-to-one" communications (c) - security officers can't hear communications between other officers. Awkward when multiple officers are involved in responding to the same security incident. Deprives officers of overall awareness of what is happening on the campus.

  • Reliant on outside party (cell phone service provider) for operation of the system.

  • Public cell phone network can be overwhelmed during times of crisis (earthquake, tornado, etc.). Service may not be available at times when it is needed most.

  • Ongoing fees for cellular service and airtime.

Our Conclusions and Recommendations


It is our opinion that the simplicity, ruggedness, and reliability of two-way radios makes them the best choice for security officer communications in most situations. Just as law enforcement and other public service agencies continue to use two-way radios, we feel that most security departments are still best served by using two-way radios over other communications devices.


The only exception is very small organizations where there may only be one security officer on duty at a time. In these cases, a cell phone is probably the only communications option that makes sense.


Tips for Using Radios and Cell Phones


  • In general, security officers should carry only a single type of communications device while on duty. If officers are issued two-way radios, the carrying of cell phones (including personal cell phones) by officers should not be allowed. An exception can be made for supervisory officers who may occasionally have a legitimate need to use a cell phone. A formal policy concerning the use of cell phones while on duty should be written and enforced.

  • All communications devices used by the security officer while on duty should be provided by the organization and not by the individual employee or contract security provider.

  • All communications to and from security officers in the field should be routed through the security command center. It is important that the command center know what security officers are up to at all times. Arrangements where employees directly contact security officers without going through the command center should be discouraged.

  • A system should be established so that all security officers in the field check in with the security command center at regular intervals, such as every hour. At small facilities with only a single security officer, arrangements should be made with an outside service to check on the status of the officer on a 24/7 basis. This can be the dispatch center of a contract security company, or an alarm monitoring company or answering service.

  • Commercial grade two-way radios on a licensed business frequency should be used for security purposes. The inexpensive Family Radio Service (FRS) radios sold in retail outlets are not suitable for professional use and are subject to interference from outside users. The price of high-quality, professional grade radios will prove to be money well spent over the long run.

  • In larger organizations, it may be beneficial for the security department to share a radio channel with other building services departments, such as facilities management, maintenance and janitorial services. There are advantages to having all team members on the same channel, especially during times of emergency. Employees of other departments can also act as informal "eyes and ears" for security and quickly report suspicious activity to the security command center. That being said, there are some times when conversations between security officers should not be heard by those outside the department. To accommodate this, we suggest that two-channel radios be used; one channel that is shared by all departments and used for routine purposes, and a second channel that can be used exclusively by the security department at times when this is needed.

  • There have been many recent security and surveillance applications developed for use on smartphones. These include video viewing and remote alarm monitoring applications. Sellers of these applications claim that they can allow a security officer to monitor and control the facility's security systems while on patrol. While there may be some uses for these applications, we feel that they are more of a novelty than a useful tool. We feel that the monitoring of security systems and the making of security patrols are two distinctly different functions, and that an officer trying to do both at the same time will do neither particularly well. Trying to monitor security systems while on patrol can be a major distraction and may place the roving security officer at risk.

If you have questions about the use of two-way radios or cell phones, or need help in designing an effective communications system for your security department, please contact us.




(a) It is possible to make and receive telephone calls with a two-way radio if a telephone interconnection unit is provided at the radio base station. While these units were widely-used prior to the introduction of cell phones, they are rarely used today.


(b) It is possible to provide two-way radios that have an encrypted signal that cannot be easily listened to with a radio scanner. Radios that have this feature are more expensive and not commonly used in most security communications applications.


(c) Some cell phone providers offer a service that they claim provides "one-to-many" functionality. An example of one such service is Sprint Direct Connect. It is our opinion that these services have many limitations and do not fully replicate the "one-to-many" capability provided by a two-way radio system.

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Published May, 2016

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