Monday, 11 August 2014

4G on the move - a simple guide for optimal reception!


Everybody knows that the 4G networks can bring huge advantages in terms of download speed over and above 3G and 2G networks, but users of 4G networks are just as likely to experience network coverage issues with varying levels of reception and signal strength depending on where they are. So what do we need to consider to ensure we get optimal reception when out and about or when we do not have access to fixed line infrastructure?

Typically, when using 2G and 3G networks, external antennas have been used to deliver increases in signal
strength to wireless devices in fringe areas of coverage. Active repeaters, amplifiers and boosters have licensing issues in quite a number of countries meaning that it can be illegal to use them without network operator consent notwithstanding the cost of the repeater, antennas, accessories etc. Using a passive (and this doesn't necessarily exclude high gain) antenna connected to the router, modem, donge or access point can provide tangible improvements in signal strength, but, depending on the type of antenna deployed, can come at a cost, so let's review the options.

There are a wide number of choices for mobile antennas depending on how or where you locate the antenna - antennas can be window-mounted via adhesive or suction cup, terminal-mounted i.e. fitting the antenna directly onto the router, modem or dongle, alternatively they can be magnetic-mounted on for example a vehicle roof. Two other slightly more permanent ways of mounting mobile antennas can be rail-mounting i.e. on a rail of a boat or screw/stud mounting where the antenna is mounted by way of an integrated stud through a hole in a flat surface (vehicle roof, product enclosure, narrowboat deck etc.).

The performance of such antennas can vary greatly. In most cases size does matter and as a rule of thumb the larger the antenna, the better performance (higher gain) that is on offer. Some antenna solutions such as magnetic antennas can be quite small, but pack quite a punch in terms of performance because they use the metal surface they mount on in order to radiate optimally (do a web search for the LTE-HIGAIN-MAG mag antenna as an example of a high gain, but smallish 4G magnetic antenna). But generally speaking, if you are deploying a very small antenna it is highly likely you will be compromising performance. Obviously though, when you are out and about the last thing you want to do is be lugging round a huge base station antenna on your back, but on the other hand you don't want to use something that is going to make little difference to your signal strength!

When using 4G services, many devices are now MIMO i.e. they have two antenna ports to maximise performance, therefore it might be prudent to consider using a 4G MIMO antennas. It must be noted, however, that most 4G MIMO antennas are not that small or portable so this may prove to be a disadvantage of this technology. The WA700_2700 window-mounted MIMO antenna from Pulse is one exception to the rule and can be suction cup mounted to a vehicle window.

Moving the signal is also an important concept. In a lot of cases it doesn't make sense to locate the 3G/4G antenna right next to the router/modem/dongle. Depending on your location, it might make sense to locate the antenna outside your vehicle, caravan, boat, narrowboat, yacht, cruiser etc and run low loss cable to the device - this means that the antenna picks up the optimal signal and whilst you may suffer a couple of dB signal loss across the cable, the net effect at the device is that the signal is stronger than if the antenna were located at the device. An example in a narrowboat is that a high gain magnetic antenna is located above deck on a metal surface (roof) where the signal is stronger and the router/modem/dongle is located below deck near the user. The much stronger signal above deck is then moved below (minus a couple of dB loss across the cable) to device meaning a net improvement in received signal strength, stability of signal and more often than not improved download speeds.

Another consideration is to locate the antenna and router/modem/dongle in an area of good signal and then use WiFi  (or even Ethernet cable) to distribute the internet access to other areas. Thereby the 4G reception is optimal and users elsewhere in the vehicle/on the boat/in the caravan use WiFI to connect.

It is also wise to check (if possible) what frequency your 4G is operating at - across Europe 4G services are being offered at a variety of frequencies including 800 MHz, 1800 MHz and 2600 MHz - so it is vital to make sure that the antenna you select does indeed support the 4G frequency you are using. For example, some 4G antennas do not operate at 800 MHz which means that in some locations you will not pick up 4G reception at all.

For further advice on your mobile 4G antenna selection, please feel free to visit our websites for a full portfolio of antenna products and RF accessories.