PART 2 - System Planning and Design

Introduction

Planning is, by far, the most important part of the job; deciding what services and equipment will be needed in each room of the house, where to mount hardware, designing each network, and developing a list of materials and cable we'll need. Planning and system design can be divided into 8 logical steps:

1. First determine the customers requirements and expectations for the installation.
2. Determine what external services are available at the house location and which to use.
3. Determine and document what services will be needed in each room based on the overall project plan.
4. Determine the outlet types and locations in each room and mark the location on the walls and a set of plans if available.
5. Determine the distribution center you'll need and its location.
6. Create a cable schedule. This is a list of each cable you'll be installing.
7. Design each network and determine the distribution center equipment necessary to support each network.
8. Finally, complete the equipment schedule with all the parts and equipment, including cable, you'll need for the job. This will be part of your overall job documentation

The steps don't necessarily need to be done in this order but this order works well. And they're the same whether you are working with a small production home or a large custom home although the process within each step will be different.

We will cover the steps in more detail.

1. Determine the Customer Requirements

First, as always, determine the customers requirements and expectations for the installation. This is part of any job and will determine the goals of project in terms of what the home owner or builders wants to achieve for entertainment, security, comfort and convenience.

2. Determine the Available External Services

Part of your job is to inform the customer what sources are available where his home is located. This means you need be very familiar with the various services and plans available from local and national service providers including everything from cable to high-speed internet service.

This isn't always easy since these services are changing all the time. You really need to keep up with current events in your local broadband world.

You'll want the prewire to support the common services that we know about today such as cable, off-air, and satellite, and in a custom home you'll want to decide which specific services to use since it will impact equipment selection and channel planning.

Don't forget to check with the builder or the local telephone, cable, and other providers serving the site to find out if there are any special requirements that you should know about prior to planning and installing the system. In some communities, two or more cables may be required to offer some cable television services or channels. It is also a good idea to get to know your local cable company engineer.

Lets take a closer look at each service to understand the planning considerations

Voice Service

While you can assume voice service is always available, it may be available from service providers other than the traditional phone company such as the cable company. Simply plan on an adequate prewire for each provider. We recommend running two coax cables to the coax NID and two CAT5 cables to the telephone NID.

Since the NID's are typically collocated, this allows either cable to be used for either service. And since fiber-to-the-home is a reality in some areas, you may also choose to run a pair of multi-mode glass fibers to the NID location from the distribution device.

Broadband Internet

Broadband internet service is available from many different sources.

• DSL from the telephone service provider
• Cable internet from the cable company
• Fixed wireless services
• And 2-way satellite service

In a production home, the prewire that you install for voice and cable service should be adequate to support broadband internet service from any of these providers. In areas where cable or DSL service are not available, or in a custom installation, you may want to prewire for fixed wireless or 2-way satellite service.

While the equipment for both services is installed by an authorized contractor for the service, you can easily prewire the installation.

Fixed wireless service will use a single RG-6 cable from the distribution center to the antenna. The antenna location will require a line of site path to the transmitting antenna.

2-way satellite service such as Hughes's DirectWay uses 2 coax cables from the distribution center to the antenna. Check with your local DirectWay or other internet satellite contractor to coordinate the prewire.

At our project house we have high speed internet access available from cable, fixed wireless, and satellite. We chose to use the local cable provider since they currently have the best access speed and rate combination.

Broadband Entertainment Sources

Outside broadband A/V sources will come from some combination of cable, satellite, or off-air broadcast. Again, the infrastructure planning should prewire for all three services.

As we mentioned in Part 1, cable operators are now offering standard definition digital channels as well as analog channels, and some are offering high definition channels. Receiving the digital channels requires a digital decoder set-top-box at the TV location. You have to obtain the decoder box from the local cable provider since they're not yet standardized. Check with your local provider to find out if you can bundle the box as part of your install.

Also at the time we made this course, cable companies are just beginning to offer HD channels over their system. This will require a new box as well.

The preferred way to connect a set-top-box to the television receiver is to connect the baseband composite, S-video, or component outputs directly to the receiver.

You can use a splitter at the receiver location to supply RF to the receiver as well to view in-home modulated channels. The viewer selects the baseband input to watch cable channels, and RF input to watch modulated channels.

Direct Broadcast Satellite

While direct broadcast satellite service was originally intended to serve customers where cable service wasn't available, it has become a major contender for cable service. Its major advantage is that it is available everywhere, the equipment cost has become negligible, service is reasonably priced, and there are hundreds of channels Both providers have also begun to offer HDTV channels from additional transponders and to offer local stations in 40 major markets.

Receiver designs have become standardized and available from many sources allowing you to purchase and install the best receiver for the job. New receiver designs output a wide variety of analog and digital baseband signals for HDTV

A key planning issue is to determine the optimum location to mount the dish antenna, preferably on the roof. The location must be free of obstructions to the southern sky at the satellite elevation for your location. Plus at least a 20 degree span to be able to see three satellites. And try to keep the antenna within 150 cable feet to the distribution center to minimize losses in the coax.

Prewire for satellite dish

Plan on prewiring four RG6 coaxial cables from the distribution center to the dish location for maximum flexibility in the choice of LNB's and multi-switches.

If you have four or fewer receivers you can use a dish with a built-in multi-switch. Or, if you have more than 4 receivers, you can use an external multi-switch in the distribution center to support as many receivers as necessary.

Satellite dish with built-in multi-switch

Multi-switch used to handle more than four receivers

If you know where satellite receivers will be located, install an extra RG6 cable from the distribution center to that location. This leaves the other coax cables free for off-air or modulated in-home sources.

Prewiring for satellite receiver at outlet

Newer satellite receivers typically have an extra LNB input for picture in a picture capability, requiring an extra cable from the multi-switch to the receiver location.

Off-Air Broadcasts

Deciding to integrate off-air television signals into the installation is a major consideration in the system design since it'll determine the channel planning you use in the installation. Remember that nearly all television stations will have converted to digital format before 2006 and many in high definition format.

Even in a production home, you should prewire for a separate off-air antenna. While you can use a diplexer to piggy-back the off-sir signals on the satellite dish cable, putting an off-air antenna where the dish is located may not be the best location.

Usually the off-air antenna should be mounted as high as practical with a clear line of sight in the direction of the transmitter site. They should be mounted on a mast well clear of other metal objects and building structures.

In a custom installation, your first step is to determine what channels will be viewed by the customer. If satellite or cable service is being combined with off-air service, you may only want to view DTV stations. These are all in the UHF spectrum meaning you'll only need a UHF antenna.

Until you're familiar with an area, the transmitter locations and signal levels available, your first step should be a visit to the Consumer Electronics Association antenna web site. The site is the result of a lot of work by antenna manufacturers, retailers, and the CEA to help consumers and installers determine the best antenna type for a particular location.

The site outputs a list of all the stations that can be received at the site, sorted by the size of antenna needed for reception and the magnetic bearing to the station. The list indicates which stations are broadcasting DTV as well.

List of stations available from the project home site output by antennaweb site

The recommended antenna types for each station are color coded from small omnidirectional antennas to large multi-element highly directional antennas.

As we mentioned in Part 1, our Broadband RF System Design and Installation (TO-05) course covers everything you need to know about antenna selection and installation in detail. Check our web site for details.

In-Home Sources

We also need to cover planning for in-home sources including DVD players, VCR's, cameras, satellite receivers, and computers. This equipment is usually clustered in an A/V equipment area such as this typically used as a home theatre.

Nearly all In-home sources of baseband video and audio that we want to distribute will require a frequency agile modulator.

If source equipment is distributed in several locations throughout the home, individual modulators at their location can be used. These will output a cable or UHF channel on the internal coax cables back to the distribution center.

If source equipment is clustered together in an entertainment center, you can use multi-channel modulators that accept up to 4 source devices. They output 4 separate channels onto one cable simultaneously.

Since this is a spec house we will prewire this entertainment area to allow a multi-channel modulator to be placed in any of these shelves, the most likely location for source equipment

Another popular video source are these small surveillance cameras, available with baseband video output or built-in modulators that output a cable or off-air channel directly, There are also cameras designed to output baseband video directly to CAT5 cable, and Ethernet networked cameras that output their video in the form of a web page. Either way, if the video is not modulated in the camera, you'll need a modulator in the distribution center.

3. Determine and Document Services Needed in Each Room

Determining what services will be needed in each room is the most important step in the planning and depends on how the room will be used and the overall project plan.

TIA-570A recommends placing a minimum of one outlet for telephone and cable in the kitchen, each bedroom, family or great room, and den or study. But that is really just a bare minimum. Work with the builder or owner to recommend additional services and outlets for multi-media and data applications.

Make sure the customer is aware of the increasing need for high-speed data access for entertainment equipment, appliances, and home subsystems, as well as broadband RF for set-top boxes, DTV tuners, and satellite receivers.

Since most houses now have multiple computers and need high-speed internet access jacks should be installed for data network access anywhere computer, entertainment equipment, even appliances will be installed.

Whenever possible perform a walk-through with the homeowner or builder to discuss how the room will be used and suggest possible outlet and equipment placement based on anticipated furniture layout. If they are unsure of a specific location, suggest that multiple outlets be installed in a room to cover all possible choices.

Portion of plan marked with locations of equipment to be installed. Numbers are used as index to equipment schedule.

Tentative locations can be marked on wall studs with a marking pen. Alternatively, you can use a set of plans with the builder or homeowner to perform the same task.

Outlets, equipment, and their tentative locations can be marked on the planes and later verified and marked in the home with a walkthrough. It is a good idea to mark the plans even if you performed the house walkthrough and marked locations on studs.

To help you label the plans, CEDIA has developed a standard set of low-voltage icons. They're available in CAD format or sticker sheets that allow the symbols to be peeled off and stuck to the plans. The sheets contain symbols for almost everything you're likely to install and provide a standardization for everyone working on the project. (Available at www.cedia.net/cgi-bin/cedia_store_access.pl)

In production spec homes you'll have to use your best judgement and TIA570 recommendations to determine what services to make available in each room

In addition to the minimum requirements, the TIA standard also recommends that additional outlet locations be provided within unbroken wall spaces of 12 ft. or more, and additional outlet locations should be provided so that no point along the floor line in any wall space is more than 25 ft. from an outlet location in that space.

Plan ahead for the customer. Many installation companies prewire to locations in the home where they anticipate the customer will want outlets in the future. This is termed speculative prewire. You perform the prewire and leave the wire in the wall, documented so it can be easily located.

If you're also doing the security system installation, you should be surveying security considerations including the locations of door, window, and motion sensors. Our project house is a high-end custom spec. home so we are working directly with the builder.

Sample equipment list showing some of the items for the project house

As Richard and I went through each room we determined what services were needed based on the use of the room, and what equipment we anticipated would be placed in the room. We also took into account the anticipated furniture layout as well as locations on the plans of counters, cabinets, doors, and so on.

As we determined the outlet locations and what services we needed at the outlet we tentatively marked the outlet on a wall stud or other easily identifiable location, and we documented the location and type on an equipment schedule (also referred to as the "equipment list"). The equipment schedule is used to document the type and location of each piece of equipment used in the job, organized by room.

For example, the outlet in the master bedroom is on the west wall and will have two CAT5 jacks for voice and data, and a coax jack for broadband RF. We also numbered each outlet. Note: the locations of every device on the equipment schedule is numbered to cross-reference it to the plans and cable schedule.

Where it is convenient we will collocate outlets next to existing electrical outlets since anything that uses the outlet will also need electrical power.

We also discussed the location for the wireless access point (WAP). This should be mounted high but not around air-conditioning ducts. We chose a central location in the top of the hall closet.

We systematically continue through the house using our plan as a guide to where devices should be located. Since we'll also be installing the security system, we need to mark the location of door/window sensors, our four security cameras, and motion sensors. We will install two of our security cameras outside, one at the front entry and one in the rear to monitor the pool. The inside cameras will be in the great room and the children's bedroom.

In the great room entertainment equipment areas we are installing multiple outlets on each shelf on each side of the fireplace for data, External coax, satellite, and modulator inputs. We'll also be installing jacks for our A-bus audio source inputs.

Since we'll be installing a distributed audio system in several rooms of the house, we need to determine the best locations for the in-ceiling and in-wall speakers and the corresponding volume controls.

Once the inside walkthrough was complete, we headed up to the roof to survey where to mount the off-air, FM, and satellite antennas. These parapet style walls allow antennas to be fairly well hidden from ground level so we want to take advantage of the highest roof level. A major consideration is how we're going to route the cables we need from the distribution center.

Back on the ground we complete the markup of the plans and make sure they correspond to our equipment list and we add any notes we made such as outlet collocation and height.

4. Determine Distribution Center Location

Next you need to determine where to mount the distribution center equipment. This can easily be one of the most difficult problems since finding space to mount equipment is difficult. Neither the builder or homeowner thinks about this requirement when building the house.

• It should be located as centrally as possible to limit cable run lengths. Remember the TIA standard limits the cable length to the outlet to 295 feet.
• It should be installed in a conditioned (living) space that's easy to get to for changes and service.
• Try to make sure the location is free of air conditioning duct work overhead and below so you have room for the cable runs.
• Avoid attics and garages due to the heat and cold.
• Do not locate close to the electrical load center panel.

In most homes you'll have to do the best you can with utility rooms or large closets like we did. We chose a location in the laundry room primarily because it is the only large wall surface that isn't in a living space. While it isn't centrally located it does give us easy access and we can install a large enclosure.

If you are working in a two story house you'll need to run cables from here to the attic so try to place the panel in a location so you can drill a chase though a common wall area up to the attic to make running the cables easy.

5. Create a Cable Schedule

You'll also need to make a cable schedule. This is an essential list of each cable used in the job, including cables for security devices, speakers, and other control systems and it will be used to perform the prewire. (Example schedule is in the back of workbook)

Sample Cable Schedule

You can make the list at the office or on the job-site (not recommended!). It has a cable identifier, the type of cable, the from and to location and how it is to be terminated, and an estimated length. For example, cable 2A is a CAT5 cable from distribution center 1 voice module 1 to outlet 2 in the master bedroom modular jack 3 and its about 70 feet.

You can add up the lengths of each cable type to know how much you need to allocate to the job and load on the truck. The number or ID of the cable is used to label the cable when they are installed. There's also a check-off column to make sure you installed and tested each cable on the list.

Once we were confident of our plan and completed our cable schedule, we created a set of tags to mark device locations on the site.

The tags contain the outlet or device designation used on the equipment schedule, the type of device or outlet, the cables that terminate at the location and specific mounting instructions. These tags not only make the job easier for the cable installation crew, but prevents a lot of mistakes by making sure the needed cable is installed at the right location, the rough-in hardware, and how it's to be mounted.

6. Design Each Network and Determine Distribution Center Equipment

Your next step will be to design each network and determine the distribution center components necessary to support them. We'll go through each network starting with the voice network.

Voice Network

The voice network simply needs to distribute at least four incoming voice lines to the various voice service modular jacks throughout the home. Each manufacturer of structured cabling products will have some type of voice network distribution module, with or without a cross-connect function.

Basic voice network design

There are two common methods used to terminate the UTP cable runs to the module. The first method terminates the cables in modular connectors. The cables then plug into a voice distribution board such as this. This modules uses a straight thru connection with no cross-connect. Or the module may have a fixed cross-connect such as this board where each row represents a different order of lines.

The other method terminates each cable in a 110-style insulation displacement connector. The connectors are wired in parallel and connected to the incoming voice lines through a similar connector. Either technique works well. You'll simply need to provide enough modules to support all potential voice outlets.

Voice network diagram used in project house

In our project house we need to support 24 voice outlets, so we'll be using 3 of these 110 style telecom distribution modules connected together. Diagram the network to show how each module will be interconnected, and which voice lines will be terminated on each module. (See our voice network design drawing in the back on the workbook)

Secondary over-voltage protection on the incoming voice lines is a good idea and most manufacturers provide this protection in some form. We'll us this surge protection module wired directly to the incoming voice lines prior to the distribution module.

Data Network

The design of the data network is also straight forward.

First determine the broadband internet access. In our case we plan on using the cable provider but will be prewired to use DSL as well. All current cable or DSL modems have Ethernet ports to connect to a router.

Second, add up all the devices and outlets that need network access. As we did our walkthrough we determined the need for 20 wired data outlets. We'll also prewire network access at thermostat locations, the security system panel, and so on. Like the voice network, you'll need to determine how the data cables will be terminated in the distribution center. We chose to terminate our cables in three termination modules. This allows jumpers to select which data lines connect to the switch ports.

Third, diagram the network to determine what equipment you'll need to support the attached data jacks and devices. Since the router seldom has more than 4 ports on it's built-in switch, you'll need to add additional switches. In our case we needed 2 additional 8 port switches.

Data network diagram used in the project house

The heart of our network will be an Ethernet router with a built-in 4 port switch on a snap-in bracket. To support wireless Ethernet devices such as laptop computers, we'll install a wireless access point in the top of the hall closet. And at trim out, we'll purchase and install the cable modem in the bottom of the enclosure.

We also want to be able to view each of the four cameras from computers as well as on TV channels. The camera server takes the input from up to 4 cameras and converts the image to a web page with a preassigned URL so it can be accessed from the in-home data network and from the internet. We'll connect it's Ethernet port directly to one of the router switch ports.

Broadband RF Network

Next we need to design and specify the broadband RF distribution system. The goal is to combine external sources with all in-home sources and distribute the combined signals so there is an adequate signal level at each external outlet.

The first step is to itemize the external source inputs that we need to support. In our case we plan on using cable service as our primary source with the prewired option of off-air digital television. We also plan on supporting satellite, but we'll talk about that later.

Then determine the total number of in-home sources and jacks and the total number of external jacks. In our project house, we have a total of 15 external cable outlets and plan on supporting 12 internal jacks for various A/V sources and cameras.

Basic diagram of RF distribution system

Start with a simple diagram of the system. Once you've done one, they're easy to modify for other jobs.

• Show all the external service inputs.
• Determine the total number of in-home sources and jacks and the total number of external devices and jacks you need to support.
• All internal coax runs are combined into a single internal source that contains all the modulated channels.
• Depending on the number of inputs, the combined signal may need to be amplified.
• The external source is also amplified and the external and internal signals are combined.
• The result is then split as necessary to support the external cable runs.

Almost all residential distribution systems will be some variation of this design.

Once you have the system diagrammed, you need to determine the source and destination signal level requirement. We use a signal level notation that lists the maximum and minimum signal level we have or need at each location. You can assume that:

• Receiver input signal level requirements are between 0 and +10 dBmV unless otherwise given by the manufacturer
• Cable company signals should be at least +3 dBmV at the NID, but expect a variation between 0 to +10 dBmV.
• Off-air signals will definitely have the widest range from -10 to +30 dBmV
• Modulators, including those built into cameras, will typically have outputs in the +25 to +35 dBmV range.

The next step is to calculate the losses throughout the system and the gains required to overcome the loss. On your system diagram, listing the loss through each passive component such as splitters, filters, and the coaxial cable. You can use a rough rule of thumb of -5 dB per 100 ft. for RG6 cable runs.

Then work backwards from the required signal levels at the external outlets applying the loss through each device to determine the signal level required at each point to overcome the loss until you get to the amplifier outputs.

Then work forward from the signal inputs applying each components loss until you get to the amplifier inputs. The gain required by the amplifiers is simply the difference between signal inputs and the required signal level at the outputs.

The diagram shows our initial design and the loss and gain calculations we did to determine the gain of the external and internal signal amplifier.

RF distribution diagram showing gains/losses through the network and required amplifier gain to overcome the loss.

We then converted that into a network design drawing showing each part we would need as well as the jumper cables between components and which cables would attach where.

You can build the system from individual components, splitter/combiners, amplifiers, filters and so on, giving you maximum flexibility. Or you can use distribution modules that combine these components for you.

RF distribution system design drawing

Since our system was more complicated than most production homes, we'll be using the individual components shown in the diagram.

We also designed the satellite signal distribution. This operates independently from the rest of the RF distribution system. We chose to provide for up to 8 satellite receiver locations by incorporating a multi-switch that operates with a DirecTV 2 or 3 LNB dish.

Finally we designed the A-bus audio distribution system. This system distributes baseband audio over two pairs of a CAT5 cable. The audio is placed on the CAT5 by a balun (an unbalanced to balanced transformer adaptor). This can be done via any CAT5 jack in the the home. We reserved used two jacks, one on each side of the entertainment center wired directly to the baseband audio distribution module in the DC3 enclosure. This uses regular punch down 110 style connectors to connect together the pairs in each cable in parallel (like a voice line distribution module.

On this module, DC power is placed on the two remaining pairs (1-pair positive, 1-pair negative).

The distribution module supports up to four locations. In our project house, we used in-wall and in-ceiling speakers in four rooms: the master bedroom, master bath, office, and dining room.

A-bus audio distribution system design

The A-bus volume controls contain a small amplifier that drives each speaker pair directly. The CAT5 cable to each speaker carries the L and R audio and power. Speakers attache to each volume control normally, through 14/2 or 14/4 stranded speaker cable.

7. Complete the Equipment Schedule

Next we completed our equipment schedule with all the parts we'll need for the job. We selected the wall plates and jacks and the distribution center network components including the distributed audio equipment. We also made a list of the type and quantity of cable we'll need from the totals on the cable schedule.

Determining Enclosure Quantity and Size

We then worked on determining the size of the enclosure we need to contain all the components.

Take the time to determine how much enclosure space you'll need for each network as well as power supplies and the room necessary for routing and securing the cable. Then you can select the enclosure height that accommodates everything with room to spare.

To save a lot of trial and error during trim-out we did a layout drawing for all the equipment we'll need for each network. The drawing shows where components will be placed and the length of any jumper cables we'll need so they can be made in the shop ahead of time.

While doing our layout design, we discovered we'll need at least two 50" enclosures for the voice, data and broadband RF networks, and an additional 26 inch enclosure for the security system and A-bus audio system.

The first 50" enclosure holds the broadband RF components and the second 50" enclosure holds the voice and data network components.

Enclosures used in the project house

Part 2 Conclusion

Planning can really make the difference between a smooth, quick installation with no call backs, and one with a lot of wasted time and customer problems. It doesn't take any more time to do it right. Once the planning process becomes a routine part of the job it will pay you back every job in time and money saved!