ZK Services

Public Safety Noise Floor Testing

​UHF public safety systems are subject to interference from various. Prior to upgrading an existing system or installing a new system it is important to understand the noise floor and potential interferers. The noise floor is needed to ensure a proper system design. Interferers must be identified and located. ZK Services performs a 24-hour test at each site using highly sensitive measurement equipment that can measure a very low noise floor. Equipment can be setup easily and remotely monitored. Green sites can be measured as well using proprietary techniques. 

 

Cellular Benchmarking

Prior to a DAS install the venue must be tested in terms of how it is affected by the surrounding macro cellsites. ZK Services uses Operator approved scanner equipment that can perform a scan of the entire range of cellular frequencies and technologies to determine which channels are transmitting in the area. The venue is walked collecting key parameters on all of the transmitting channels. All channels for each Operator are plotted for each level or section of the venue. In addition, CSV files are provided for direct import into RF Design software such as iBwave and others.

 

CW and PIM Testing

Typically a short time after the benchmarking test is done and an initial system design is complete the CW and PIM tests need to be performed. Data from CW and PIM testing is used to fine tune the DAS design. ZK services owns CW test transmitters for all cellular bands with a wide range of output power. Multiple frequencies can be transmitting simultaneously making the testing go quickly. Coverage plots, csv files and PIM reports are delivered for each frequency and each CW/PIM location.

 

System Validation

Once the DAS is installed and operating a validation test is performed to test the user experience. Handsets are typically used in addition to scanning for this test. Voice and data calls are performed to test quality and data speeds. Channels are also scanned for coverage. ZK Services provides a custom report indicating the performance level and comparison to requirements for the venue.

 

Quality of Service (QoS)

For networks that are up and running a QoS test is extremely valuable. This test consists of performing hundreds of voice calls and data transfers in order to determine call statistics such as blocked and dropped calls, audio quality, data throughput rates and other parameters that are important to user perception A detailed report along with an executive summary is provided identifying problem areas and offering suggestions for improvement.

 

E911 Location Testing

In emergency situations first responders need to know the location of the wireless caller. ZK Services assists the E911 technology providers in testing and improving the wireless location algorithms and technologies.

 

Problem Identification and Solving

In some cases problems in the network cause disruption in quality of service and a third unbiased party is called in to identify the cause. ZK Services has many years of experience troubleshooting RF issues and can provide key data and recommendations in solving network issues. 

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WiFi

Wi-Fi access points and networks are installed in almost every building these days. Some cities have area-wide free networks while some venues like airports have free and paid access. Whatever the case, Wi-Fi networks can be as simple as a single access point or as complicated as a multi-zone, multi-frequency network delivering high capacity data and voice services.

 

In venues that provide Wi-Fi to demanding users in sports stadiums, schools, airports, hotels and others it is critical to test the performance as seen by the Wi-Fi user. Most Wi-Fi testing measures signal strength coverage but this does not provide the complete picture. Signal level can be excellent yet data throughput can be poor. It is vital to test the Wi-Fi network as seen by the actual user which means testing the actual data rates while the user is stationary as well as when the user moves around the venue from AP to AP.

 

Many things not related to signal strength can affect the user perception of quality and data speeds. ZK Services has specific Wi-Fi collection measurement and analysis software from leading vendors that provide the complete pucture of service quality and root cause analysis to our clients.

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Public Safety

The highest priority for Fire and Police in terms of safety is quality communications. Fire services personnel need to know where everyone is in a burning building. Police need to communicate in order to catch the bad guys, it's what gives them the advantage.

 

It is important to know that once inside a building you can talk to others and know where they are, even in the stairwells and elevators. This does not just happen, it requires planning, execution and testing of wireless communications systems.

 

ZK Services has test equipment specifically dedicated to testing the public safety and two-way radio channel quality and coverage. High quality scanners measure signal levels and custom test radios measure channel quality parameters DAQ (digital audio quality) and BER (bit error rate). Data can presented in grid patterns as called for in P25 requirements.

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