When discussing technology designs for homes and workplaces, I commonly get asked about the need for network cabling, especially where video streaming is concerned. Questions can vary from “Why do we even need cable when there’s Wi-Fi?” to “Is Category 6 data cable enough when Category 8 cable is coming out?” There are many myths to dispel around this, and this article will clear this up and make recommendations for your network environment.
“Why do we even need to run data cable when there’s Wi-Fi?”
The use of streaming video is rapidly increasing. Since it requires a guaranteed data transmission speed, and consumes the most network bandwidth, we’ll look at
- the various video sizes
- how fast data needs to transmit for video streams of these sizes
- the speed capabilities of data cable and Wi-Fi networks.
Video sizes
Standard video sizes are shown in pixels and aspect ratios. (Click on the image for original size).
As televisions and displays continue to grow in size there will be far greater demand to ensure correct network infrastructures are in place to guarantee data speeds.
Video speeds
The speed of data in networks is measured in Mbps (megabits per second). For some of the video sizes shown above, required data speeds need to be as follows:
Note that video streaming is always a variable experience as it’s dependent upon the codec used. Also, the amount of data being sent will vary from frame to frame, depending on the complexity of the image and the number of changes between frames at the time.
Data cable and Wi-Fi speeds
Compare the required data speeds above, to the actual or typical data speeds of various data cables and Wi-Fi standards below. This is an easy indicator for the minimum data and Wi-Fi networks required for your video application. (Click on the image for original size):
Note: All category cable types use Twisted Pairs of copper wires hence all cables types end with TP. The first letters are used to describe the type of screen around them. U = Unshielded, S = braid screen or Shielded, F = Foil Shield.
“Is Category 6 cable enough when Category 8 cable is coming out?”
Category 7 and 8 Cable
Thicker cables (Cat 7 and above) with better shielding are ideal for industrial situations. They are more suited to data centres, than residential applications since they lack flexibility.
Category 7 is a shielded cable solution normally installed with non-traditional connectors that are not backward-compatible with category 3 through 6A. It is usually terminated with 8P8C compatible G45 connectors, or with TERA connectors. Fortunately shielded RJ45 connectors compatible with CAT6, CAT6A and CAT7 Solid and Stranded Cables have become available. Category 8 is the next UTP cabling offering to be fully backward compatible.
Category 8 is designed only for data centres where distances between switches and servers is short. It is not intended for general office cabling.
Wi-Fi
As you can see in the chart above, the theoretical speeds of wireless networks differ greatly from the actual or typical results found in real world environments. This often causes confusion for buyers who believe that their 802.11ac wireless router is going to effortlessly allow multiple streams of 4K/UHD video throughout their home.
The 802.11ac Wi-Fi standard is often referred to as Gigabit Wi-Fi as it theoretically exceeds 1 Gbps. It’s actual speed maxes out at 200 Mbps though. Many users typically experience 70 – 100 Mbps.
The Wi-Fi Alliance is looking at 802.11ac’s successor, 802.11ax. 802.11ax should deliver real-world speeds above 2Gbps. In a lab-based trial of technology similar to 802.11ax, Huawei hit a max speed of 10.53Gbps, or around 1.4 gigabytes of data transfer per second. Clearly, 802.11ax is going to be fast. It is unknown though when this standard will become readily available.
Network Equipment
All consumer grade (and most commercial grade) network equipment, such as routers, motherboards and Ethernet cards currently max out at 1000 megabits or 1 Gbps. For the time being, and likely years to come, users will not be able to take advantage of the 10 Gbps and faster speeds that Cat6a and higher cables are specified for.
Most home users use the Wi-Fi router supplied via their ISP, which by default is not a highly specified device. As an example, my home router is specified as 802.11b, 802.11g and 802.11n (2.4 GHz only). While the data transmission rates for these Wi-Fi standards are officially stated as 11 Mbps (802.11b), 54 Mbps (802.11g) and 300 Mbps (802.11n with an external antenna), those data speeds are actually around 5.5 Mbps, 20 Mbps and 35 Mbps respectively.
A single 4K video stream, requiring 15-20 Mbps, will either kill your Wi-Fi or at best consume most of the capacity of a commonly supplied Wi-Fi router, allowing very little, to no room, for anything else.
It’s for this reason alone that companies who manufacture 4K capable entertainment devices, like the Apple TV 4K and Google Chromecast Ultra, require a data cable to their Ethernet ports. This is the only way to ensure the quality of a 4K video stream.
Recommendations
If you want guaranteed 4K video for your new 4K or UHD television, make sure you have data cable run to it’s location – your current Wi-Fi network will NOT be sufficient.
Cat 6 cable is still the industry standard for homes and offices and is likely to be for quite a while. With its capacity for 1 Gbps up to 100 meters and 10 Gbps up to 37 meters, it will definitely ‘”future-proof” your environment for a very good number of years to come. If you want guaranteed peace of mind then spend a little extra for category 6a.
Once 802.11ax Wi-Fi becomes available it will easily handle streaming 4K video (15-20Mbps) within its +2Gbps capacity. Even if Netflix begins streaming 8K in the next few years 802.11ax has more than enough bandwidth. This will definitely resolve the bandwidth issues for the majority of older homes that do not have a home network cabling infrastructure.
Until 802.11ax becomes available, upgrading your Wi-Fi router to 802.11ac is the next best recommendation.
Last, but not least, choose a home automation designer or workplace technology consultant to design a complete data cabling strategy. You will save yourself regret sometime in the future.
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Synergy Environments is the blog of Dean Murrell. He is a Christchurch, NZ based designer of audio visual and automated technology for organisational workspaces and residential homes. Feel free to contact him via the contacts page should you need further help and advice.