Communication Technologies

1. Setting Up an Ad-Hoc Network

Ad hoc networks, in the context of Wi-Fi and tethering/personal hotspots, refer to a temporary network connection set up for a specific purpose, usually in a limited area.

These networks are “decentralised”. This means that each device is independent and can function as both a transmitter and a receiver. There is no need for a specific central device like a router or wireless access point.

Two primary ways to set up ad hoc networks are through open Wi-Fi networks and tethering/personal hotspots.

• Open Wi-Fi – This refers to a Wi-Fi network that does not require a password to join. A user can create an open Wi-Fi network in the Wi-Fi settings on their router, allowing anyone within range to connect.
• Tethering/Personal Hotspot – This involves using one device (often a smartphone) to share its internet connection with other devices. You can set up a personal hotspot in the settings menu of your mobile device, which then can be connected to by other devices through Wi-Fi, Bluetooth, or USB.

There are some clear benefits to setting up an ad-hoc network in these examples. However, there are some clear disadvantages to ad-hoc networks that make them not suitable for most situations.

Advantages

• Simplified connection – It is easier to connect devices together so setting up the network is quicker and simpler. This is very important in situations where the users are not very IT literate.
• Reduced costs – It is less expensive as the lack of a central access point such as a home router. This saves us the money of purchasing this device. It also means we don’t need to carry an additional device around with us.

Disadvantages

• Slower performance – Ad-hoc networks are slower than traditional networks. This is because devices using the ad-hoc networking mode usually only support slower transfer speeds.
• Weaker security – They are usually less secure due to commonly using wireless connections (which are less secure than wired ones) and there is no central device for managing the security of the network.

2. Security Issues with Open Networks

As convenient as ad hoc networks may be, they come with a significant risk: security. Open networks lack the security mechanisms of password-protected networks, making them susceptible to unauthorised access and misuse.

Specifically, open networks don’t have encryption. Encryption is where your data is jumbled up to make it unreadable should someone manage to intercept your data. We’ll learn more about encryption later in the course.

Here are some specific issues:

• Data Interception – On an open network, an attacker can easily intercept the data that you send and receive, including sensitive information like credit card numbers and passwords.
• Malware Distribution – Attackers can also use open networks as a platform for distributing malware, infecting connected devices.
• Unauthorised Access – With no security barriers, attackers can gain access to your device through the network, manipulating data and settings.

3. Performance Issues with Ad-Hoc Networks

A major limitation of ad-hoc networks are the performance issues that these networks suffer from. There are a number of performance issues, most notably:

• Maximum Speed – ad-hoc networks cannot transfer data as fast as networks in infrastructure mode as they have a smaller maximum data transfer speed. The speeds can also be affected by the increased interference.
• Maximum Range – wireless routers have higher-powered antennas and so can provide much greater ranges than wireless connections directly between devices. Other methods of ad-hoc networks like Bluetooth and USB cables have very short ranges too. Further, when in ad-hoc mode, operating systems usually hide the signal strength indicator.
• Interference – ad-hoc networks produce a lot more interference when many devices are connecting as each has its own connection with devices often moving around and crossing signals. This interference can increase the corruption of the data being transferred, which means this data will need to be re-sent. This can reduce range, lead to dropped connections and reduce speed.

4. Issues Affecting Network Availability

Network connections, most notably your connection to the internet are not equal across the entire world. There are many issues that will affect the availability and performance of both mobile broadband and traditional broadband for end users.

Below we will go into several issues that can affect the performance and availability of networks:

Location of the Network

Cities are likely to have excellent network coverage as, due to the higher population levels, telecom providers will invest far more in these areas.

This includes having far more phone masts offering mobile broadband connectivity as well as providing access to superfast broadband, including FTTP (Fibre to the Premises).

This will mean that for those in rural areas you may not have fast fibre-optic broadband in your area and 4G mobile broadband, and even if you do, the speeds will be significantly poorer.

In the case of mobile broadband, it’ll also be more like that you will get dropouts where your internet stops working.

Developed vs Developing Countries

The issues discussed above are even more true of the difference between developed and developing countries.

Developed countries will likely provide excellent network coverage as money will be appropriately put into developing these networks.

Developing country often won’t have enough money devoted to its countries network infrastructure to provide coverage across the country and modern broadband speeds.

The image below shows the difference between 4G availability in Zimbabwe and the UK. Red areas indicate the availability of 4G broadband.

Available Infrastructure

The state of network infrastructure in an area significantly affects network availability. This includes the physical hardware like cables, towers, satellites, routers, as well as software systems managing these networks.

Regions with well-developed, modern infrastructure usually offer reliable, high-speed connections. If the infrastructure is outdated or poorly maintained, it can lead to slow speeds, frequent disruptions, and limited coverage.

Mobile Network Coverage

Mobile network coverage can also affect internet access, especially in areas without wired connections. Similar to general network infrastructure, mobile coverage is usually better in densely populated urban areas and can be spotty in rural locations.

Generally speaking 4G broadband covers around 90% of the UK landmass, but this can vary a bit depending on the provider.

Factors such as the distance from the nearest cell tower, the frequency band used by the service provider, and physical obstructions (buildings, trees, etc.) can impact the quality of mobile network coverage.

Blackspots

A blackspot is an area where network service is unavailable. This could be due to the lack of available infrastructure, but it can also be due to physical barriers.

Geographical features like mountains, valleys or hills will disrupt wireless signals as the signals can’t pass through solid stone. This can be similar in big cities with buildings made of thick concrete, where signals will have an equally tough time getting through.

We could find that our mobile broadband connections will drop out while travelling from things like passing through a tunnel, which would stop anything we’re downloading and could cause us to lose something we’ve been working on.