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Push-to-Talk Over Cellular (PoC)

What is PoC? 

PoC provides group communication services over both Wi-Fi, 4G and Long Term Evolution (LTE) technology, creating a nationwide radio network that utilizes the cellular infrastructure of Mobile Network Operators. This enables radio networks with very wide coverage areas. Radio users are untethered by the range of repeaters and base stations used in traditional radio networks. 

The concept of Push-to-Talk over Cellular was introduced by Nextel in 1987 as an alternative to two-way radios. Nextel revolutionized business communication when it started to pass small voice packets across their iDEN network. Prior to PoC, business communication was dominated by two-way radios on peer-to-peer and local radio networks. Nextel was acquired by Sprint, and in 2013 Sprint decommissioned the Nextel iDEN network. 

Today, PoC provides the best of both narrowband digital radios and broadband 4G/LTE networks. PoC radios support the advanced features of Digital Mobile Radios (DMR), including messaging, instant group calling, GPS location tracking, and emergency notifications. Combining this functionality with Wi-Fi and 4G/LTE cellular networks provides the national coverage area and bandwidth required for modern data and video applications.

How PoC Works? 

PoC is also referred to as Radio over IP (RoIP). Similar to Voice over IP (VoIP), RoIP devices are handheld two-way radios that access cloud based PoC services via the internet for voice and video calling. A data plan SIM card (similar to those used in cell phones) is installed in the PoC device to enable access to the internet using the 4G/LTE cellular infrastructure of Mobile Network Operators like AT&T, T-Mobile, and Verizon. 

PoC radios are also known as Internet of Things (IoT) devices that access the internet for data communications and can also access the internet via Wi-Fi networks like any other mobile device. 

This alphabet soup of terminology gets confusing, but simply put, PoC devices access the internet through 4G/LTE cellular networks and Wi-Fi networks  for wide-area radio communications. The result is access to existing and reliable networks that require no maintenance or operational expenses. An app on the PoC device (typically an Android operating system) provides simple and convenient access to PoC services. 

PoC network services are typically hosted on the cloud using PoC controllers (network appliances) that are operated by a PoC platform service provider. PoC controllers can also be privately owned and operated by the customer. Gateway routers provide

connectivity between the 4G/LTE network and the cloud hosted PoC controller. Dispatch Applications and the Management Application (used to configure customer accounts) are connected to the PoC cloud server through the internet. 

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PoC Group Calling



PoC provides the same group calling capabilities as traditional two-way radio systems to enable instant group calls to multiple users with the press of a PTT button on a radio or from a dispatching application 


Call groups are set up based on all call and emergency calls, types of employees (supervisors, administrators, etc.), remote employees and mobile service fleets, employee locations, type of projects, etc. Radio users can belong to multiple groups as shown in the overlapping areas. 

PoC Features and Benefits 

Flexible Single-Site, Multi-Site, and Nationwide Coverage

PoC devices connect to cellular 4G/LTE networks with the installation of a SIM card. PoC devices can also connect to Wi-Fi networks for single-site deployments (that do not require SIM cards) or multiple Wi-Fi sites can be connected over an IP Network or VPN. 

No Radio Infrastructure or FCC Frequencies Required

Since the network infrastructure for PoC is existing cellular 4G/LTE and Wi-Fi networks, there is no need to purchase, operate and maintain any traditional two-way radio network equipment. This reduces capital equipment costs and day-to-day operation and maintenance costs. PoC also eliminates the need for FCC radio frequency licenses, and in high-density urban areas there may be no frequency spectrum available. 

Rapid Deployments

PoC systems can be deployed very quickly over existing cellular and Wi-Fi networks. PoC radios can work out-of-the-box with SIM cards pre-installed, and system configuration is done through an easy-to-use web-based dispatch application. 

Instant Push-to-Talk Communication 


PoC technology enables subscribers to make one-to-one (individual) calls or one-to-many (group) calls to separate groups of people at the same time. One press of a button on a rugged handheld device and you are talking to a predefined group or an individual. 


GPS Location Tracking and Dispatching 

PoC devices with integrated GPS enable location tracking via a dispatcher application. This is an essential tool for managing, scheduling, and tracking remote teams in real time. PoC dispatch applications that support Geo Fencing enable alarm triggers when, for example, employees enter hazardous areas, or when remote service employees stray from defined territories. Dispatchers are typically web-based applications allowing for easy deployments and minimal start-up costs. 

Who Uses PoC? 

Enterprises and organizations which use PoC services are looking for wide-area workforce communications with low start-up and operational costs. PoC is particularly useful for businesses with multiple locations, mobile workforces, and vehicle fleets. PoC also provides a cost-effective solution for organizations where traditional Land Mobile Radio (LMR) solutions do not support broadband applications, and the availability of licensed radio frequency spectrum is limited or unavailable. 

  • Security Professionals

  • Facility Managers

  • Fleet Managers and Drivers

  • Occupational Health Managers

  • General Managers 

  • Logistics Managers 

  • Maintenance Crews 

  • Custodial Staff


PoC is also an excellent option for any organization that is currently using traditional two-way radios. Since LTE has excellent nationwide coverage, and Wi-Fi is nearly ubiquitous in all buildings and facilities, PoC provides a reliable and cost-effective radio communications solution. 

  • School and Universities

  • Hospitals

  • Convention Centers

  • Factories and Warehouses

  • Office Buildings 

  • Hotels and Resorts

  • Agriculture

  • Transportation and Logistic


PoC Devices vs. Smartphones


Organizations may choose to have employees use personal smartphones or company-issued smartphones for internal company business communication. BYOD smartphones can be used as PoC devices with an Android app installed on the device. 

Companies may have employees using smartphones as pus-to-talk devices for group communications, but there are several advantages to providing employees with dedicated PoC devices. 

  • PoC devices are service plans are much less expensive than smartphones and cellular plans

  • PoC devices ensure employees use the devices exclusively for business-related communications and reduces the distractions of personal smartphones

  • Instant Push-to-Talk group and individual calls without launching apps, looking up contacts, or waiting for users to answer the phone

  • PoC mobile computers are compact handheld devices that run Android business apps

  • PoC mobile radios and handheld radios with car docking kits are safe and legal to use while driving

  • PoC devices provide features typically not supported on smartphones: 

    • Rugged devices that withstand high impact (dropping), water submersion, and dust

    • High volume speakers and noise canceling technology for use in loud environments 

    • High power batteries that guarantee calling availability for the entire work shift 

    • One touch emergency alarms for worker safety


PoC Dispatching Applications

PoC systems include we-based dispatching applications that can be run on a web browser. Dispatch applications provide a comprehensive fleet dispatching and group calling interface for instant nationwide voice and video calling and GPS location tracking. Group calls can be made to pre-programmed groups, or dynamic call groups can be built by selecting users from a list or within an area on the dispatch map. 


Dispatch applications can track multiple user locations and travel routes with job site time stamps to manage and dispatch remote workers. Dispatchers can draw geofences on the map to define boundaries for territories and service areas. Alarms can be generated when users enter or leave a geofenced area. Note that location tracking is GPS based, which does not track locations of indoor users in a large facility like a convention center. 

Subscription Based PoC Services

PoC radio services can be purchased on a subscription basis. The subscriptions are available as monthly plans or 2 year plans.  The plan payments can include the cost of the PoC devices, or the PoC devices can be purchased in full by the subscriber and just pay the monthly HALO fees. (ask a Sure-Response representative for more information on bundles, plans, and costs.) Wifi use with PoC devices is optional when at a stationary place. 

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Hytera HALO includes a powerful web-based dispatch and fleet management application that tracks driver locations and travel routes with time stamps. The dispatch application works with the GPS built into Hytera PoC devices and supports geofencing capabilities.

Hytera HALO Dispatch supports group calling

as well as individual calling. Dynamic call groups

can be quickly created with a simple list selection

or geographically by selecting an area on the dispatch

map. The dispatcher may stun (turn off) and 

reactivate a radio and receive emergency 

alarms. (ask a Sure-Response representative about 

the additional costs of adding HALO Dispatch 



Hytera HALO Dispatch

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