Recently, much attention has been given to the importance and challenges related to testing brownfield environments for Triple Play services. Interestingly, many forget that greenfield sites can be equally as challenging. Not for the same reasons, of course.

Greenfield situations can be tricky because they seem simple. In reality, the same essential tests used in brownfield deployments must be completed at greenfield sites as well. This article examines greenfield deployments, discusses how they differ, the unique challenges they bring, and how proper testing can ensure fast, reliable completion.

Brownfield vs. Greenfield Environments
Brownfield sites comprise of existing communities, existing customers of a particular service provider, and an existing, fully operable copper plant and telecommunications infrastructure. These fiber-to-the-node (FTTN) sites generally require upgrades to legacy equipment and wiring in order to expand, improve, or deploy new services.

Essentially, a brownfield deployment presents challenges associated with the performance and upgrade of systems in existing, fully developed communities. Typically, this involves an overlay of new fiber integrated with existing distribution copper, identification and correction of issues within the premise, and verification of new services.

On the other hand, a greenfield deployment refers to the installation and configuration of a telecommunications network and services where none previously existed, such as new housing developments. Greenfield installations benefit from the use of new fiber-to-the-premises (FTTP) plant, structured cabling terminated at Smart Panels, and wires dedicated to specific services.

Since new cabling and infrastructure equipment is required in greenfield deployments, service providers have an opportunity to choose the right cabling in each home for the services that will be offered: traditional copper or fiber-to-the-home (FTTH). In addition, technicians may benefit from knowing where cables start and terminate, which goes to each room, and whether or not the community is built to accommodate wireless networks.

While they might think it is seemingly an ideal situation, service providers and technicians must still exercise care not to act on the assumption that everything works just because it’s new. In other words, it comes down to the quality of the builder’s installation contractor.

In brownfield deployments, technicians must deal with a concoction of various telephone jacks in one or multiple rooms and, usually, a similar assortment of coaxial cables.

In greenfield applications, the number of outlets may increase exponentially. Each room in the home may have multiple unshielded twisted pair (UTP) and coaxial wire runs. This wiring is installed by a contractor who may have only a basic understanding of telecommunications services and technology. As a result, the wiring often has to be redone or corrected if not installed properly, significantly increasing deployment time and costs. In addition, the fiber drop usually terminates at the side of the house, requiring technicians to terminate it at the optical network termination (ONT), which takes time and skill.

Depending on the builder, some new homes are outfitted with CAT5 or better wiring and coaxial cabling that run from the network interface device (NID) or Smart Panel to every room in the house. A Smart Panel is a central location where each of the cables terminates, which provides distribution and control of telephone, data, and video (TV, cable TV, and satellite TV) signals throughout the premises. When cables are properly terminated, these panels enable technicians to identify and determine which telephone lines (phone/fax/computer) go to each room and which rooms receive TV, cable TV, or satellite TV signals. In addition, the panels make it easier for technicians to relocate signals quickly and easily based on the homeowners’ preferences.

Four Steps to Video/Voice Victory
Despite clear differences in brownfield and greenfield sites, these four tests, required to ensure proper deployment and operation of Triple Play services, are virtually the same in either situation.

Test 1: ONT Verification
Most greenfield installations are FTTP. Once on private property, the signal typically travels the final distance to the service provider’s end user’s equipment in an electrical format. The ONT converts the optical signal into an electrical signal such as HomePNA Alliance (HPNA), Ethernet, or Multimedia over Coax Alliance (MoCA). For FTTH and for some forms of fiber-to-the-building (FTTB), it is common for the existing phone wiring or coax to connect directly to the ONT. The ONT is usually located on the side of the home or at the minimum point of entry (MPOE).

Before any in-premises testing is started, the technician must verify that the ONT was provisioned properly and that a valid data stream exists at the ONT’s Ethernet, HPNA, or MoCA ports. Using test equipment, the technician can plug into these ports to verify services. If TDM or VoIP voice service is provided by the ONT, the technician should also verify connectivity by placing and receiving a call directly from the ONT. Once verified, the technician is ready to test inside the house.

Test 2: Cable Identification
Inside, technicians first must determine and verify which cable goes to each room. Unfortunately, despite being a new installation, technicians never know what they will find at each site. A good pre-wire installation company will ensure that every cable is laid out, labeled, and ready for the next step. The reality in most situations may differ, however.

Many times, field technicians may find piles of cables that look more like a rat’s nest as some installation companies pay by the wire. In these cases, the installers’ motivation was to get in and finish with the job as quickly as possible. (The more wire run in a day, the more money they make.) As a result, they tend to run cables right into the central location without identifying them.

In the ideal situation, a builder would facilitate a meeting between the service provider and the cable installation company prior to construction so they can map out exactly what is needed. Alternatively, service providers could also reach out to builders about 6 months before the sites are ready for wiring.

Providers can use the following rule of thumb to determine when the wiring contractors should be contacted: normally, wiring contractors start work soon after framing is completed, but before insulation is installed. If drywall has gone up in the building, it is probably too late to change the outcome of the wiring job. When builders and telecom companies work together to identify needs and develop a plan prior to construction beginning everyone wins.

Believe it or not, technicians may find a home that has 8, 10, or even 12 jacks scattered throughout the house, when in reality only 4 are necessary: 1 for each set-top box in each of 4 rooms, for example.

During cable identification, it is imperative to connect only those jacks that will be used, and to disconnect any previously wired jacks that aren't needed. This eliminates vacant cable runs that act as an antenna and cause noise ingress and other disturbances later on. These 2 tests can be used for this purpose:

Option 1: Some test platforms include cable identification devices, which plug directly into the outlet and are numbered for easy identification. Once set up, the technician goes to the main splitter and connects a test set to 1 individual cable run at a time. The test set will then read out the number and identify the room where each cable terminates. All cables should be clearly tagged or labeled to save time during future service visits.

Option 2: The second option can be used in place of cable ID devices. If service is being provisioned in a multiple dwelling unit, the technician may use a tone generator that attaches at the customer's living unit and use a receiver wand at the main feed to identify their customer's cable. All the technician needs to do is wave the receiver wand across the termination point and listen to the set tone to identify which feed belongs to their customer.

Test 3: Cable Qualification
Once cables are identified, technicians can start verifying services. This requires end-to-end tests and measurements to determine whether or not there is any signal loss over the coaxial cables. If a CAT5 or an Ethernet connection is used, technicians must verify performance against 2 different cabling standards, TIA 568-A and TIA 568-B, each having different RJ45 pinouts. Regardless of the preferred standard, technicians must ensure that only 1 is used consistently throughout the premise. Technicians should perform complete tests to validate their company's chosen standard, thereby preventing any shorts or crossovers, and confirming continuity. (See Figure 1.)

As part of qualification, it is imperative to conduct a coax cable loss test to ensure the cable supports the frequency range required by the kind of digital signal to be transmitted. For example, HPNA usually transmits from 4 to 28 MHz. At these frequencies, the expected signal loss over RG-6 and RG-59 coaxial cable is about 1 to 1.2 decibels (dB) per 100 feet of coaxial cable. Most average-size houses will have wire runs of this length or shorter. The intent of cable loss testing is to send a set of frequencies from a source transmitter at a known and repeatable level. The test set acts as a receiver and calculates the difference between the power sent from the transmitter and what the test set received.

Tests that indicate 3 dB of loss or more indicate three possible problems that if not rectified during deployment can become amplified over time: a bad F connector, a splitter, or a bad cable. Trouble associated with F connectors is usually due to improper installation. Once corrected or replaced, if the loss is still 3 dB or more, it is likely that there is a hidden splitter, probably installed to add wiring that may have been missed or forgotten during the initial installation.

Splitters are normally found only in brownfield environments, but can turn up in greenfield sites as well, underscoring the need to check every part of the installation. A single splitter generally may be left in place for wire runs going to set-top boxes if they are of acceptable quality. If the signal loss is due to impairment, the coaxial cable needs to be replaced. This is extremely rare in a greenfield environment. The number one cause of cable loss is usually at the termination points, not with the cable itself.

During cable qualification, technicians should also check to be sure that F connectors are compression type, barrel connectors are securely connected, and that all wiring is properly terminated and tightened using a torque wrench. When it comes to F connectors and barrels, when in doubt, swap them out.

Test 4: Service Verification
Once cable qualification is complete, technicians should perform a final all-encompassing test to verify that the service performance is of the highest quality. Service verification tests will help ensure that no imperfections exist that can escalate over time and result in multiple service calls.

Since most greenfield installations are Ethernet, service verification is straightforward. Technicians should complete basic tests, verify the cables and that the IPTV works, and run standard tests using advanced test sets that send packets to every node on the home network. This verifies maximum bit rate, signal-to-noise ratio, received errors, etc., and checks real-life performance.

For HPNA and MoCA installations, point-to-point and whole home testing verifies that each cable run and all devices are in good working order.

These proof-of-performance tests stress the entire home network to verify that weak links do not exist.

Victory Is In The Details
While many times technicians may go into greenfield sites expecting faster, simpler installations, the reality is that the same essential tests used in brownfield deployments must be completed at greenfield sites as well. Working on the assumption that installation teams delivered fully functional cable runs can lead to problems in the future, and costly truck rolls for troubleshooting and maintenance.

As Triple Play services evolve, new and improved test systems will make their debut, attempting to help reduce or eliminate provisioning and maintenance challenges. Whether working in a greenfield or brownfield site, one of the most significant decisions is whether or not to use a selection of à la carte tools or an all-in-one solution. Some technicians prefer one brand of test gear over another, but learning and carrying a collection of different test sets may reduce efficiencies offered by the equipment that tests all aspects of the Triple Play service. For the service provider and even pre-wire installation contractors, an all-in-one test set lowers the total cost of ownership by eliminating the need to acquire and maintain multiple test sets for each technician. For technicians, all-in-one test sets simplify each deployment by ensuring the right tests are available for every situation they may encounter in brownfield or greenfield sites.

The important thing to remember is that completing thorough testing and performance verification before turning new services over to the customer is essential.

About the Authors

Yumi Kato is a Product Marketing Manager at Sunrise Telecom. She has been with the company for 5 years, focusing on copper, optics, and access products. Previously, she worked at Agilent Technologies, NeoPhotonics and Optiva. She holds a bachelor's degree in Physics from the University of California, Berkeley, and a master's degree from Santa Clara University.

Ken Fridley has 20 years of experience in the telecommunications industry working in line, management, and technical support staff roles.  Ken has authored numerous job aids, training packages, and articles regarding IPTV, VoIP, and FTTx deployments. He is currently a regional systems engineer for Sunrise Telecom Inc. headquartered in San Jose, California. He can be reached at kfridley@sunrisetelecom.com. 

Sunrise Telecom is a developer of innovative communications test and measurement solutions for telecom, cable and wireless service providers. For more information please visit www.sunrisetelecom.com.

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