Networking 101: When To Use (And Not Use) A Network Repeater

While a home wireless network was once a luxury, these days it has become an essential technology for most modern homeowners or apartment dwellers. The challenge has become to have a strong signal to the router throughout the residence, which can support high bandwidth activities, such as streaming HD video and gaming.

While many current routers transmit a good signal, Wi-Fi was designed to be an unlicensed, low power system, and easily degrades as the distance from the router increases, and with objects in the way. Additionally, the newer 5.8 GHz frequency, does not propagate as well as the older 2.4 GHz frequency due to differences in wavelength penetration.

Finally, working against the network is interference from a variety of sources including microwave ovens, cordless phones, and most commonly, nearby Wi-Fi networks. Yes, your neighbor s wireless networks are often competing and interfering with your network. In a busy high rise residential building, users can detect literally dozens of networks traversing their apartment, making it difficult to find a free channel to have a device connected to the router.

Given this myriad of challenges, it is nothing short of amazing that Wi-Fi works at all. With the goal of having a good signal everywhere at the house, in some cases the signal put out from the router does not reach out fully across the property. With additional challenges of having wireless internet access in areas further from the router, such as by a pool or shed in the backyard, this becomes too tall of an order for even the best placed, and most robust router with multiple antennas.

Enter the Repeater

A solution advocated by the networking gear manufacturers is known as a repeater. This is a device that is designed to act as an intermediary between the router and the device that needs a signal (known more properly as a client). The idea is that the router sends out the signal, the repeater then retransmits it, and the client receives the repeated signal that remains strong. When it is time for the client to transmit data back to the router, the process is reversed, with the repeater acting as the Go between.

There are two types of repeaters. The first is a dedicated hardware repeater that only can perform this one function. The other is that some routers can be configured via their settings to function as a repeater. In general, a dedicated repeater is preferred, and is also more compact as most of them are designed to fit into a power outlet, taking up little more space than a night light.

At first glance, a repeater might seem like a good approach to the problem of a fading signal from the router. However, this solution for a better signal is fraught with several downsides.

The first downside is that a repeater needs to both send and receive the data. This translates to the bandwidth effectively being cut in half. For example, if the repeater supports a data rate of 300 Mbps, then the download is limited to 150 Mbps, and the upload is 150 Mbps. Realize that these are theoretical maximum numbers, and in actual use, the rates will be even lower. And let s face it- no one really wants to take such a big hit to their bandwidth just to get a signal!

Some advocate daisy chaining a series of multiple repeaters to try and pass the signal along to a location distant from the router. However, with an understanding of how the bandwidth falls off while utilizing a single repeater, it becomes evident how the bandwidth will get serially reduced through multiple repeaters. For example, it drops by 25% with two repeaters, and 12.5% with three repeaters, and so on. Again, with users looking to maximize their bandwidth, this quickly becomes folly.

Another downside relates to the placement location. If the repeater is too far from the router, the signal from the router will be too weak, and the speeds will be slow, or even drop out. The solution would seem to place the repeater to a closer location to the router. However, this can also be detrimental as the signal from the router and the repeater can interfere with each other, and overall reduce the speeds of all the devices on the network. Some newer repeaters feature LED lights on them to assist in optimal placement, but the older gear does not.

The final downside are the frequencies supported. Most repeaters are limited to the 2.4 GHz network, and do not support the newer 5.8 GHz frequency. This also means that the advantages of 802.11ac, the newer Wi-Fi standard in use, such as beamforming, when put through the repeater, get lost. Over time, this may change as newer repeaters that are 802.11ac compliant get released, but for the time being, this is a limitation for a significant chunk of the existing gear.

So, Do I Need a Repeater?

So bearing in mind the limitations above, but given the persistent need for ubiquitous wireless coverage, is a repeater on a network a viable solution? The answer is an unqualified, definite maybe.

On the one hand, there are multiple options that are better than a repeater, which avoid the bandwidth reduction. Solutions that come to mind include running new CAT cable, Powerline networking, or additional access points. In most situations, any of these options would be preferable and more robust; in some cases a combination of the mentioned solutions may need to be used, such as combining Powerline networking to provide a connection for an additional access point. However, depending on the solution chosen, it may end up requiring additional work, more expense, or both.

On the other hand, a repeater may have a use in a limited number of situations. In a situation where running new Ethernet cable is not an option, and Powerline networking cannot be used either, for whatever reason, then a repeater may be the only practical solution. The other caveat to adding a repeater onto the network is that the bandwidth needs are more basic, realizing that the throughput on a repeater will be diminished by at least 50%. In other words, don t plan on streaming 4K video through a repeater.

In conclusion, it is important to understand the limitations, as well as use case scenarios for a repeater on a network. Keeping in mind that the repeater is often the networking gear of Last resort to be added to a home network, at least in certain cases, it is potentially useful.

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