This is part II of my guide to planning and installing a structured cabling system in your home. I had a lot of interest in my first post and will answer a few questions that people have asked me. There has also been a great deal of interest and discussions on Geekzone lately relating to home cabling so hopefully these posts will help a few people when it comes to planning a system for a new house or renovating your existing property.
Why use cat5e rather than cat6 cable?
Cat5e cable is Gigabit certified and the cable lengths that will be in an average house will deliver Gigabit Ethernet. Cat6 does of course have higher bandwidth capabilities and if price isn't an issue then there is no harm in running Cat6 cable. For an average household however many people do consider it overkill and you do have to be aware that you have to be a lot more careful with the cable when running it near power or other cables as any advantages will be cancelled out if the cable is installed poorly and you'll end up with cable that doesn't deliver any performance gains over Cat5e.
What sort of coax should I use?
The minimum you should be using is RG6 duo shield. This is the minimum spec for any satellite installs and offers a good price/performance ratio. There is plenty of cheap Chinese made RG6 around these days that many people believe is poor quality however I've never used it so can't comment. If you're in doubt look for something that has Sky TV or Sky Certified printed on it or stick with a good brand such as Belden. You should be able to pick good cable up for around 75c + GST per metre if you ask around at wholesalers such as Mastertrade or Corys and there is a booming market for cable on Trademe. Typically RG6 coax is sold in 100m or 152m rolls which is potentially a more than you will require for an average household so it’s really a matter of shopping around for the best deal to suit your requirements.
If you live in the Wellington, Christchurch or Kapiti area and will be using Cable TV or Cable Modem services from TelstraClear then you need to install quad shield RG6 as this will allow you to run their services over your structured cabling if it has been installed to an acceptable standard. TCL will not hook their service up to duo shield cable under any circumstances due to possible RF ingress. Quad shield does have the disadvantage of costing quite a bit more than duo and if you're not in an area with TCL services there aren't any real gains from using it unless you are running cable over very long distances or live in area that suffers from a lot of RF interference.
Also avoid using cheap screw on RG6 connectors as these are terrible. You should only use RG6 crimp, radial or compression connectors which will cost around $1 - $2.00 each depending on where you get them from. Avoid DSE at all costs as you’ll pay upwards of $6 for a RG6 compression connector! To fit these connectors you will need a suitable tool which will set you back anywhere from $20 - $60 depending on where you purchase it from (there are a few popping up on Trademe)
My electrician thinks its overkill!
What I have talked about in Part I of this article isn’t overkill – it is what Telecom have been recommending as the minimum specifications for all new residential dwellings in New Zealand for quite a few years now. Their guidelines recommend that all cabling should be a minimum of Cat5e wired to all bedrooms and living areas in a star configuration back to a central point and that RG6 be installed for TV/Pay TV services.
There seem to be plenty of electricians out there who are completely oblivious to these guidelines and still continuing to connect phone jack points in a daisy chain configuration and believe this is perfectly acceptable. The reality is that it's not and they should be moving with the times. If you’ve got an electrician who insists that this is “how things should be done” and that your suggestions for a structured cabling system is overkill I’d recommend finding one who isn’t stuck in the dark ages!
Before proceeding with any cabling there is some essential reading to be done on the Telepermit website. PTC's 103 and 106 both provide a wealth of information and the guidelines that you should be working to when planning and installing either a basic home phone system or a structured cabling system in a residential dwelling.
What about all of the off the shelf structured cabling systems on the market?
There are also plenty of off the shelf structured cabling systems available from electrical wholesalers with models from Sigtec PDL and Hills being the most commonly available in New Zealand. Many of these units are being heavily promoted at present and most architects and electricians will be aware of them. If you are looking at one of these you do really need to be aware of the capabilities and limitations of these units.
Cat5e cable is capable of more than just voice or data. You can now buy baluns that allow carrying component or HDMI video signals over twisted pair cabling and as people move towards large flatscreen TV's they want a quality picture on the screen. Over the years many people have distributed Sky TV around their house by looping the RF output into a splitter and running that to their bedroom over coax. Most of these commercial structured cabling units (such as the Sigtec, Hills and PDL etc) all use a modulated composite output from your DVD player or Sky box or set top box to deliver TV content to all rooms running over coax. This method is however unable to deliver a quality picture from your DVD when you're running into a large widescreen TV and is incapable of delivering HD content around the house.
The claims that these systems make of being “able to watch Sky TV from every room in the house” are true but their systems aren’t going to deliver you a quality picture.
These days if you're really wanting to distribute a quality picture around your house you need to look at component or HDMI - HDMI will be the only way of sending HD video around the house if as expected the the ICT flag is enabled on HD broadcasts by Freeview and Sky TV in New Zealand. Enabling the ICT flag means component video is output at a standard definition 576i and not in 720p high definition output.
To distribute component or HDMI video around the house you require baluns that will allow the transmission of component and HDMI video over regular Cat5e or Cat6 cable. Two baluns are required for a single cable run – one plugged into the output of the device (such as a Sky decoder) and one plugged into the RJ45 socket at the other end with a cable running to the TV. Due to the high bandwidth requirements of HDMI you need to use dual Cat5e runs to do this however component video can be sent over a single cable. HDMI and component amplifier/splitters are also available that can drive multiple displays from a single output so it’s possible to distribute a component or HDMI output to multiple TV’s in your house. Remember that HDMI also includes both HD video and 7.1 audio in a single cable so you can deliver extremely high quality audio and video over dual Cat5e cables.
All of these units are based on modular units for both video and twisted pair cabling and do allow flexibility however the it's hard to recommend buying any of the commercial off the shelf home cabling kits in their typical configuration. I’m sure I’ll get somebody who’s a fan of these units knocking me for the comment but the harsh reality is the usefulness of their video distribution capabilities is now becoming very limited for the reasons described above, and not enough emphasis is being put on the importance of twisted pair cabling.
Many of their units still only include 8 way patch panels which are nowhere near enough ports, even for a small house. Twisted pair cabling has become a solution for phone, data and video distribution and you have to remember that cable you are running in a house now is about future proofing your house, not just meeting today’s requirements.
The wall mount cabinets that all of these companies make however are nice and make an ideal wall cabinet for mounting your own hardware and I would recommend buying one of these cabinets and buying a 16 or 24 port patch panel to fit inside it, along with one of their telephone distribution modules which are compact and can be jumpered directly across to your patch panel using a Krone 110 to RJ45 cable. I have chosen to go down the path of installing a regular 19" patch panel mounted to the wall which also allows for installing a 19" switch below it which is an identical setup to my own house.
One great thing that most of these companies also sell are IR modules for sending IR signals from your remote control to other devices around the house, this allows you to control your DVD player or set top box. These also run over Cat5e cable so just remember - you can never have too much cable in your house!
What about VoIP?
VoIP isn’t just a buzzword, it’s the future of telephony. A lot of people still don’t realize that within a few short years that Telecom’s planned NGN network is going to fully replace their existing PSTN network and existing phone exchanges and that every phonecall will be using VoIP technology.
If you’re a TelstraClear InHouse customer in Wellington, Christchurch or Kapiti you’ve always been able to use their cable modem service for internet and not require a standard phoneline.
If you’re a Telecom customer it’s always been a requirement to have a phoneline to be able to have an ADSL broadband connection. This means you have to pay approximately $45 per month for something you may not use. Naked ADSL is now available and means you can sign up for ADSL broadband and not require a Telecom phoneline – you can use a VoIP provider for all your telephone calls.
There are two ways to move to a VoIP connection – buy new VoIP phones to replace your existing phones (around $150 minimum per phone) or buy a router or ATA (analogue telephone adapter) that allows you to keep all of your existing phones. True VoIP phones such as the Linksys SPA922 or SPA942 are simply hooked up to your home network and connect to your VoIP provider over the internet whereas an ATA such as a Linksys PAP2T or SPA2102 connects to the VoIP provider over the internet and converts the call and allows you to plug a standard phone into the unit. If you’re using an ATA or router and a structured cabling system you can install this unit in your cabling cabinet and simply patch the outputs into your patch panel.
The only downside with VoIP connections is that if your power goes out you also lose your broadband and phone connection so it’s not a bad idea to allow space near your cabinet to install a small UPS which can run your router and ATA will insure you’re still able to make phonecalls during a power cut.
Hopefully this has given people a few ideas when it comes to cabling their house. I do want to emphasise however that I don’t do cabling as a day job and I’m sure there may be plenty of other tips that people have (and probably a few people who disagree with me!). If you've got any questions about wiring your own house feel free to post in the Geekzone Forums as there are plenty of people on the sight with a lot of knowledge that will be happy to help you or offer advice.
Check back for Part III when I show you how to finish the wiring in the house.
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