Local Area Networks (LAN) are everywhere. From home offices to large corporate and industrial complexes, everything is networked. While the components of these networks receive a lot of attention because of their expense, the cabling is often overlooked. It is estimated that 50% of all network problems are caused by the cabling. The cabling can be in the wall, floor, ceiling, outlets, interconnects and/or patch panels. This has created the need for Cable Testers to confirm that the network can successfully carry traffic at the rated speed.
A few questions need to be answered before the appropriate Cable Tester can be selected.
What type of cable is to be tested? Twisted Pair, Coax or Optical. When testing Optical cable, it must be determined whether it will be Single-mode or Multi-mode.
What connectors or cabling is required? If copper, what patch cords are required? If optical, what connectors (LC, SC, ST, FC or other)?
What speed is the cabling being tested for? Standard tests for the various network speeds have been established by the Telecommunications Industry Association (TIA) and the Organization for Standardization (ISO). The TIA Standards are referred to in categories (CAT 5, 6, 7, etc), while the ISO Standards are defined in Classes (Class, D, E, F, etc). Testing speeds can range from 100 MHz up to 900 MHz.
What level of testing is required?
Certification - Guarantees compliance to industry standards
Qualification - Primarily used as a troubleshooting tool
Verification - Verifies basic connectivity
Once you have determined the Cable Testing Solution required, you will need to plan your acquisition strategy. If your project is short-term then an equipment rental may be your best solution. Rental allows you to scale to project size and scope, minimize capital outlay and quickly replace a down unit. If your project is long-term, or of a repetitive nature, a lease or purchase may be a better option.
A few links are listed below to provide more detailed information.
TRS-RenTelco: LAN Cable Testers (CAT 5, CAT 6)
http://www.trs-rentelco.com/SubCategory/LAN_Cable_Testers_CAT_5_CAT_6_.aspx
Fluke Networks: Cable Testing Basics
http://www.flukenetworks.com/fnet/en-us/featuredTopics/Cable+Testing+Basics.htm
Thursday, January 7, 2010
Wednesday, November 18, 2009
3 Steps to Successful Drive Testing
You’ve got the people, some experience in base station installation & maintenance and now you received an RFQ from the Wireless Provider for drive testing, now what?
The first step to success in drive test is to understand what the Provider needs from the contractor. Drive testing generally falls into 1 of 3 phases: planning, optimization and bench marking. Determining the phase of the project quickly defines the test equipment necessary to get the job done right. Planning takes place prior to installation of the base stations in an area. This phase will be very important for the Provider as it will set the stage for success of the network being deployed and will generally involve less technical measurements. Optimization will occur once the base stations are deployed. It will involve more technical analysis of the signal from the base station. Bench marking will be the most complex and will require measurements of multiple Provider signals in the desired test area.
The planning phase requires both a transmitter (BVS Gator, Andrew-Grayson Invex3G) and a receiver (Agilent Drive Test, Andrew-Grayson Invex3G). You will need to know the frequency range over which the Provider is going to carry its network. Most of the test transmitters are 20W units with varying carrier frequencies and channel steps that follow the channel plans for the various mobile standards. Antenna types will also vary by Provider and mobile standard, so getting the right combination of transmitter and antenna will be important. Once the test transmitter and antenna are installed, drive testing can begin. The receiver needs to measure basic signal levels, RSSI. Current mapping software, utilizing GPS, creates a visual picture of the signal strength overlaid on a map of the desired test area. Changing the orientation of the antenna or placement of the antenna, and driving the route again, will show improvements if necessary.
Optimization begins after the base stations are turned up. For optimization, phones or devices (wireless cards) and scanners (Agilent Drive Test, Andrew-Grayson Invex3G) are used to collect more detailed data. Most scanners or the software associated with the scanner are mobile standard specific. You will need to specify both the frequency and standard being tested. You may also see terms for the various parameters associated with the scanner technology, such as: PN, Pilot, BSIC, DVCC, etc. The scanner information identifies which base station covers the area. In most cases the phones will be supplied by the Provider. At the least, valid SIM cards are required. The phone may contain special firmware known as NetMon or test modes. It is important to verify that the drive test hardware and software supports the phones or devices used. Special interconnect cables exist for some devices as well. The drive test system will be limited to a number of devices, so knowing the total number of devices required for the test is important. The information collected during an optimization drive test creates opportunities for the Provider to make software and hardware changes to the base station for better coverage. Changes to the base station often lead to new contracts for optimization drive testing.
Last, but not least, bench mark testing presents the most complex and exciting opportunity for drive testing. All of considerations for optimization come into play again for this type of test plus the necessity to make measurements on several Provider networks at the same time and collect additional data. These drive test systems by their nature will be more complex and will require additional hardware and software options. At this stage, quality of service (QoS) measurements (Andrew-Grayson Invex3G) are often made. Generally referred to as mean opinion score (MOS), additional software and sometimes access to plain old telephone (POTS) lines might be necessary.
Once you have determined the test equipment required you will need to plan your Drive Test Equipment acquisition strategy. If your project is short-term then an equipment rental may be your best solution to minimize the capital outlay required to complete the project. Drive test equipment rental gives you the flexibility of quickly scaling the number of crews you have assigned to the project while at the same time limiting the amount of equipment you need to purchase to support the contract. In the event of test equipment failure, renting the equipment from a top-tier supplier will provide you with the ability to quickly swap a down unit. Test equipment rental companies generally handle all of the repairs, maintenance and calibration of the equipment. If your project is expected to last over twelve consecutive months, a lease or purchase may be a better option.
Now it’s time to get past the basics and configure a system. Take a look at the following sites to get started:
Good luck!
The first step to success in drive test is to understand what the Provider needs from the contractor. Drive testing generally falls into 1 of 3 phases: planning, optimization and bench marking. Determining the phase of the project quickly defines the test equipment necessary to get the job done right. Planning takes place prior to installation of the base stations in an area. This phase will be very important for the Provider as it will set the stage for success of the network being deployed and will generally involve less technical measurements. Optimization will occur once the base stations are deployed. It will involve more technical analysis of the signal from the base station. Bench marking will be the most complex and will require measurements of multiple Provider signals in the desired test area.
The planning phase requires both a transmitter (BVS Gator, Andrew-Grayson Invex3G) and a receiver (Agilent Drive Test, Andrew-Grayson Invex3G). You will need to know the frequency range over which the Provider is going to carry its network. Most of the test transmitters are 20W units with varying carrier frequencies and channel steps that follow the channel plans for the various mobile standards. Antenna types will also vary by Provider and mobile standard, so getting the right combination of transmitter and antenna will be important. Once the test transmitter and antenna are installed, drive testing can begin. The receiver needs to measure basic signal levels, RSSI. Current mapping software, utilizing GPS, creates a visual picture of the signal strength overlaid on a map of the desired test area. Changing the orientation of the antenna or placement of the antenna, and driving the route again, will show improvements if necessary.
Optimization begins after the base stations are turned up. For optimization, phones or devices (wireless cards) and scanners (Agilent Drive Test, Andrew-Grayson Invex3G) are used to collect more detailed data. Most scanners or the software associated with the scanner are mobile standard specific. You will need to specify both the frequency and standard being tested. You may also see terms for the various parameters associated with the scanner technology, such as: PN, Pilot, BSIC, DVCC, etc. The scanner information identifies which base station covers the area. In most cases the phones will be supplied by the Provider. At the least, valid SIM cards are required. The phone may contain special firmware known as NetMon or test modes. It is important to verify that the drive test hardware and software supports the phones or devices used. Special interconnect cables exist for some devices as well. The drive test system will be limited to a number of devices, so knowing the total number of devices required for the test is important. The information collected during an optimization drive test creates opportunities for the Provider to make software and hardware changes to the base station for better coverage. Changes to the base station often lead to new contracts for optimization drive testing.
Last, but not least, bench mark testing presents the most complex and exciting opportunity for drive testing. All of considerations for optimization come into play again for this type of test plus the necessity to make measurements on several Provider networks at the same time and collect additional data. These drive test systems by their nature will be more complex and will require additional hardware and software options. At this stage, quality of service (QoS) measurements (Andrew-Grayson Invex3G) are often made. Generally referred to as mean opinion score (MOS), additional software and sometimes access to plain old telephone (POTS) lines might be necessary.
Once you have determined the test equipment required you will need to plan your Drive Test Equipment acquisition strategy. If your project is short-term then an equipment rental may be your best solution to minimize the capital outlay required to complete the project. Drive test equipment rental gives you the flexibility of quickly scaling the number of crews you have assigned to the project while at the same time limiting the amount of equipment you need to purchase to support the contract. In the event of test equipment failure, renting the equipment from a top-tier supplier will provide you with the ability to quickly swap a down unit. Test equipment rental companies generally handle all of the repairs, maintenance and calibration of the equipment. If your project is expected to last over twelve consecutive months, a lease or purchase may be a better option.
Now it’s time to get past the basics and configure a system. Take a look at the following sites to get started:
Good luck!
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