Mobile internet technology is progressing at unprecedented speeds and the sheer variety of concepts out there quickly lets one lose sight of what is right for each situation.

Yachting has some core 4G / 5G requirements to solutions compared to commercial maritime, corporate and public sector Wireless WAN technology. Aesthetics, symmetry and sub-optimal spaces with ever increasing coax cable lengths are important factors to consider.

Two factors are critical for a high-speed 4G/5G experience, MIMO (Multiple In – Multiple Out) and the high frequency bands, both which require good signal reception and the appropriate installation design. 4G/5G UE (user equipment) uses low powered transmissions (as per regulations) and having low loss cabling with the shortest cable length is crucial, having a high gain antenna MIMO antenna is paramount.

We’ve seen installers try to compensate a 20-30m long coax cable run and the resulting huge signal loss, by installing an amplifier before the router. What is misunderstood is that a lot of these amplifiers operate in grey areas / prohibited zones. Every nation has their own regulatory authority and many either ban these amplifiers from the networks or at least require a registration of the amplifier at the governing authority.

Another misunderstood fact about amplifiers, while they do amplify and subjectively extend the range, they also amplify interference received. The actual throughput gain in speed is very low with no or minimal additional throughput. Amplifiers by principle break the theory of MIMO, which incorporates the signal interferences received between multiple antennae. The amplified signal is much more likely to be unusable for the subtle signal differences required for MIMO functionality.

What is MIMO? It is one of the most crucial changes in LTE technology for bandwidth, but also probably one of the most important key features in terms of speed improvement for Yachts as a lot of other features build up on it or benefit through it. The underlying principle is for the base stations (BS) to be able to send multiple data streams parallel from two or more antenna to the user equipment (UE) on the downlink.

Being able to send multiple streams over the same physical time-frequency resource in the world of wireless data transmission means higher throughput as the very limited available resource frequency bands get used more efficiently – it’s like a one lane street getting extended to two lanes, meaning more cars can frequent the road at the same time. This is how data rates of 300 or more Mbit/s can be reached as hypothetical data rates double with each stream compared to one.

Stream separation for MIMO can be achieved in several ways, signal difference / diversity, is based on two separation concepts summarised below:

• “Spatial Diversity” or the interference at line of sight. In the signal path between base stations (BS) and user equipment (UE), the signal wave will get interference by buildings, cars, trees and other objects. What used to be feared to reduce speed and range is now embraced, as the diversity between the signals received by the spatially separated antennae is then compared to separate the streams as the chance is greater that one stream signal is better than the other.

 

• The other separation concept is “Polarisation Diversity” which means that the base station (BS) is sending the signal with a 90° offset between the antennae, like one wave going “up and down” and the other wave going “left to right” (but it is usually a “X-crossed polarisation”), the issue with X-polarisation on mobile deployments is that the MIMO beneficial reflection of the waves on obstacles over long distances result in the polarisation of the wave to shift, which can make the isolation too low for MIMO functionality. This is why X-polarisation and especially vertical/horizontal antennae are mainly used for fixed installations such as buildings, especially e.g. long-range WLAN deployments. X-polarisation is not commonly used for mobile applications such as vehicle routers, maritime vessels and mobile phones.

Whilst X-polarisation is the easiest way to use large MIMO deployments it has some drastic downsides. X-polarised antennae are most commonly sector or directional antennae, emitting signal gain into a limited sector or direction. There are a few omnidirectional X-polarised antennae but their signal gain is generally a lot less than non-polarised antennae, common good X-polarised antennae have up to 3 dBi gain, while there is very high gain linear antenna, often up to 5 dBi gain. As a reference 3dB means a doubling of the signal or halving of the signal power.

Using linear MIMO antennas.

Using multiple antennae for beams is beneficial because the ideal signal will be chosen by the modem and in this way increase range. In more recent releases, base stations (BS) will also use active beam forming capabilities, meaning that massive MIMO base station (BS) antenna arrays are able to send signal beams directed towards the user equipment (UE), this way further increasing range.

Using modern multiple 2×2 MIMO antennae (each antenna has multiple antennae combined RX & TX) which often utilises both of these separation concepts. This becomes a crucial element to benefit from MIMO, that antennas are carefully fitted and positioned to maximise LTEA speeds. Together with Carrier Aggregation, the modern MIMO antennae has to serve a broad band of frequencies, while delivering the separation and sensitivity for diversity usage. MIMO antennae have to:

•             Use appropriate cabling and connectors to reduce signal loss and signal noise
•             Spatial separation
•             Correct polarisation
•             Proper frequency range designs

It is crucial to know these facts as taking, “short cuts” through compensating with bad antennae, long coax cable runs, amplifiers, reduced antenna numbers through signal combiners / splitters for multiple modems will introduce more errors and performance loss. In these areas of dynamic, fine-tuned signal and frequency handling “overcompensation”, it is rather harmful to the achievable performance onboard.

The perfect solution would be a 4×4 MIMO deployment of 4 modems (enclosed within a single router or two routers if feasible), the absolute ideal deployment for high speed 4G/5G operations would be 8 dedicated, high gain 2×2 MIMO marine antennae that are evenly spaced out by 3 to 5 meters in every direction of the vessel: AFT/BOW/PORT/STBD with as short and ideally very low loss cable runs as possible to make best use of reflections and shadows created by the vessel itself, with the router in a central location between the antennae with the focus on short cable runs.

Although we would love to design and install that for every yacht, on a closer look it would be very difficult and often only with high installation costs, questionable symmetrical aesthetics, so a workable solution is favourable. MIMO’s solution to this is the Mi-Dome. The Mi-Dome contains 16 high quality, 5 dBi high gain antennae in a dense but well-planned environment with the router inside, resulting in minimal coax cable runs. The Mi-Dome can easily be positioned on a high point on the mast to give maximum possible range to the horizon, similar to VHF waves, the electromagnetic waves of 4G/5G cannot bounce – “the earths curve is the limit”. All enclosed within a 60cm dome this allows the use of an existing dummy dome on the mast, replacement of a Fleet Broadband dome and can be created as a bespoke solution to meet the atheistic requirements of the vessel with multiple size dome solutions available.

MIMO Connect – Unlimited & Caribbean / Global 4G LTEA Solutions

The demand for fast and reliable connectivity is increasing daily, not only for yacht owners, guests and crew, but for all consumers globally. Staying connected has become a necessity and need, not just a nice to have. Due to these increasing demands, MIMO Connect have been thinking ahead of how we can deliver this requirement to the client with fast, stable and reliable results in a cost-effective manner.

COVID-19 has further enhanced the need for connectivity, with clients locking down onboard with their families, to remain in touch with the office, remote schooling and communicating with loved ones via video call. Moving our lives to a virtual platform (such as Zoom, Skype etc.) in conjunction with the usual demands of internet browsing, social media and streaming, cyber security also became an important consideration. Rather than using a potentially compromised marina WIFI connection many clients relied on their 4G / VSAT services and therefore during this period, it certainly showed the increasing importance of a secure connection.

Due to this increasing need, MIMO Connect have been working closely with the various network providers and have now delivered the new Unlimited 4G LTEA SIM for use in Europe, USA and the French Territories of the Caribbean.

To deliver this unique service, the team have been negotiating the contract for the Unlimited SIM for an extensive period with the networks, to provide clients with a commercial grade, tier 1 and unthrottled SIM which is now in use on multiple vessels throughout Europe and the USA. The service is provided as a SIM only contract and/or included with a MIMO Connect 2 or 4 SIM modem solution, further enhancing the user experience to deliver UK and/or US fixed IP addresses to allow clients to enjoy the at home experience of browsing and especially entertainment access.

Following the uncertainty of the 2020 Mediterranean season, we have seen a certain shift that the Caribbean season will be proceeding as “normal”. Whilst the season will be proceeding, the 4G sector has changed drastically since the 2019 season. The significant change is how the networks locally are working with roaming SIMs; therefore, clients will experience (with some carriers) a very poor service, plus significant increase in costs.

To overcome the potential issues clients could experience, MIMO Connect have created a new multi SIM solution, including a new premium Caribbean only roaming solution. In 2019 service in the Caribbean was intermittent, therefore by creating a multi SIM solution including a premium level Caribbean only roaming SIM this will ensure clients will receive the best experience onboard.

Connectivity is becoming more and more important every day. Speed and reliability first, but delivered in a cost-effective manner for the client. This is the MIMO Connect philosophy, wherever a client is globally to deliver the best service always, the client doesn’t need to be in the Mediterranean, USA or Caribbean to achieve this….

For more information on the MIMO Connect Unlimited Data Plan and/or the Caribbean / World Data Tariffs please contact the team on sales@mimo-connect.com.