Potential technologies and solutions

Mobile hardware

1. Smartphones and tablets: almost all modern smartphones and tablets can ‘hotspot’, where the device creates a local Wi-Fi network and acts as a router, allowing other devices (typically 5-10) to connect to the internet through its data connection

2. Dongles: are becoming less popular, as hotspot capability becomes ubiquitous in smartphones and tablets. Dongles can still be useful for laptops without SIM capability where a smartphone hotspot is not a
useable option.

3. Mi-Fi: is a generic term used to refer to small battery powered dedicated hotspot devices which use mobile connectivity. Although Mi-Fi units can have complex networking features, most are fairly simple.

Although convenient due to their size and mobility, these devices tend to have less networking features than fixed devices and smaller or built-in antennas, which reduce the effectiveness of both the Wi-Fi and the mobile signals.

Fixed Wireless Access (FWA) is the term used to refer to a wide variety of routers that are intended to be situated in a semi or permanent (fixed) location, like a remote office or portacabin and would include either an antenna on the device itself and/or one or more external antenna mounted on an exterior wall or roof.

The FWA modems and routers provide 4G and/or 5G connectivity, come in all sizes and form factors and provide many different features and options to suit most needs:

• different form factors such as desktop, external (like weatherproof) and industrial
• different numbers of SIM slots for multi-SIM options
• different arrangements of LAN and wide area network (WAN) ethernet ports
• different power options (PoE, DC or AC)
• multiple antenna ports for both mobile networks and Wi-Fi networks
• different ingress protection against environmental elements

These fixed wireless routers have many more networking features than mobile hardware, and have options for external antennas, which can then be connected to an equally large array of internal or external antenna options to help boost both Wi-Fi and mobile signals

Network providers

For a mobile connectivity solution, the most important choice is signal strength and availability which will be largely determined by which mobile network provider is selected. . In addition, as a back-up service is based in a fixed location and the coverage should be predictable and stable, there are some considerations to making the right selection:

Network providers

As most organisations do not have contracts for connection services from all mobile network providers ) temporary prepay SIMs can be purchased and used as short-term validation of network performance to support decision making.

Coverage maps

Although detailed coverage maps are available from the mobile networks online and an aggregated version is available from Ofcom to research predicted network coverage, these are only indicative and do not provide network quality, throughput, and stability. Indoor coverage is provided by using a simple algorithmic approach based on standard signal degradation and cannot take specific environmental factors into account such as building material, number of dividing walls, signal reflection. See Wireless infrastructure: Building guidance for health and care organisation for more on this topic.

Testing

As coverage is only one element of network performance, persistent performance testing (such as the free service hosted by www.testmy.net) over a number of days should be undertaken, as network coverage maps are only indicative and do not display network quality, throughput, and stability at different times of the day.

If a multi-SIM approach is being adopted, then network provider choice will be greatly influenced by the purpose of the multi-SIM

If multi-SIM is being chosen for resilience and failover, then it will be more appropriate to choose different network providers for different SIMs. If using a Mobile Virtual Network Operator (MVNO) you should check to confirm that the underlying network is provided by a different network provider.

If multi-SIM is being chosen for greater bandwidth through bonding of multiple connections, then it is likely more appropriate to choose a single provider as the network characteristics (such as latency and jitter) are more likely to be aligned and produce better bonding. 

For more on SIM types and capabilities see Connectivity for peripatetic health care workers.

Mobile Virtual Network Operators (MVNO)

Use the underlying network of one of the main four mobile network providers, so do not require separate analysis when determining the best network for your organisation.

“Roaming” SIMs 

Which originate from mobile network providers outside of the UK, can provide marginal coverage advantage over UK provider SIMs, as they can utilise any UK network operator, although they are generally more expensive and best suited to non-fixed location use cases.

Charges

For mobile back-up solutions, charges are an important consideration as charges accumulate whilst SIMs are sat idle. Low line rental options are usually off-set with higher usage (i.e. data charges) and there are many data usage options available, such as unlimited, shared, or pooled data bundles. The various tariff options are also likely to be driven by the specific customer requirements and existing commercial relationships.

Multi-SIM FWA routers are becoming increasingly popular and provide a wide choice to buyers. However, it is important that buyers research the router’s and provider’s capabilities to understand what they are getting. The two main benefits of buying multi-SIM routers are:

Resilience or failover

In this situation, if one SIM fails to obtain a signal, the other should take over the connection. This needs to be automatic, although the trigger for switching is usually a total loss of connection, rather than a degradation of signal quality or throughput.

Load balancing

Load balancing is a technique used to distribute network traffic across multiple connections to ensure high availability, efficient utilisation of resources, and improved performance. Load balancing is a large topic itself, and in-depth review is outside the scope of this guidance, although different routers will perform different types of load balancing. Some FWA routers will load balance devices or applications between different SIMs, but transport layer bonding, where multiple SIMs are bonded to produce a single data pipe , is less common. Specific protocols and services, such as multi-path TCP (and the newer MPTCP over Quic) are available to facilitate bonding at the transport layer and this is also the reason that some providers have an overlay VPN service as the two streams of data need to be re-assembled at the providers cloud server before delivering to the end client server.

Most business-grade FWA routers will provide all of the expected networking features and settings.

Mobile based routers have different WAN settings to fixed broadband routers. The SIM card has the required user authentication built-in, although as some WAN settings are network specific (such as Access Point Name (APN)), some network specific credentials are required and may need to be set manually on the router (although more advanced routers will recognise the network from the SIM card and auto-configure).

Inbound initiated connections will not work as per fixed broadband. Although the router may have the standard settings, like Network Address Translation (NAT) and Dynamic DNS, these features are very unlikely to work with a standard SIM on mobile networks, as network providers use their own NAT to mask numerous SIMs behind a single externally facing IP address. If inbound connections are required to an FWA router and the site, then special private APNs (with static IPs or Dynamic DNS) will be required at extra expense.

Some providers of FWA routers also offer cloud management dashboard and interfaces, which are particularly useful for remote management and configuration of FWA routers or groups of FWA routers without the need for fixed IP SIMs.