England

Please tell us where you live so that we can provide you with the most relevant information as you use this website.
If you are at a BFPO address please choose the country or region in which you would ordinarily be resident.
Accessibility statement
An image to illustrate Communications technology module
Electronic communication is ubiquitous in homes, offices and urban environments. You probably regularly use mobile devices, Wi-Fi and broadband. What makes such forms of communication possible? How do they relate to each other? Why is their performance so variable? This module gives you an insight into these and other questions by looking at the fundamental principles of communications technologies. Through these principles, you’ll gain an insight into the possibilities and constraints of modern communications technology.
Block 1
Block 1 concerns the physical aspects of signals and their environment. You will study the theory and practice of signals (such as how electrical and radio signals can represent data), the propagation of signals through space and materials, and the physical media used to convey signals, such as optical fibres, free space and conducting materials. Issues of noise and spectrum availability are ever-present because they limit what is possible. Accordingly, you will study and use Shannon’s theorem, which specifies the maximum rate at which information can be sent over a channel of a specified bandwidth in the presence of noise. You will also study some concepts from Fourier’s theorem, which shows how an information-bearing signal occupies a band of frequencies rather than a single frequency.
Block 2
The second block concerns the nature and types of codes used to represent digital data. Although digital data is thought of as a succession of zeros and ones, the way those zeros and ones represent data needs ingenuity because perfect transmission in the presence of electrical noise (or interference) is impossible, and noise is unavoidable. In practice, the probability of error must be made sufficiently low, and this is achieved by error-detecting and error-correcting codes, which add extra zeros and ones to the data. You will study some primary coding methods used to add resilience to signals. You will also look at some techniques used to reduce the amount of data imperceptibly so that files can be compressed.
Block 3
The final block looks at the principal types of access networks in use. These are the networks used to connect users to the primary data and telephony trunk routes. They include mobile data (3G, 4G and 5G), DSL broadband (the type delivered over a user’s fixed-line telephone connection), Wi-Fi, optical fibre and coaxial cable. The basic principles are covered to uncover their similarities (such as the increasing adoption of orthogonal frequency division techniques) and the factors that affect the performance of these types of networks. The block concludes by examining the implementation of security and virtual private networks in teleworking.
You’ll get help and support from an assigned tutor throughout your module.
They’ll help by:
Online tutorials run throughout the module. While they’re not compulsory, we strongly encourage you to participate. Where possible, we’ll make recordings available.
Course work includes:
We regularly review the assessments in our modules, so we may update the examination method used for this module to an in-person exam or a remotely invigilated (proctored) exam. When we are making such a change, we will make it clear on this page. If we need to make a change after you have registered, we will notify you as soon as possible. If you have additional requirements, we will support you to complete your assessments.
You’ll have access to a module website, which includes:
Additionally, the website includes:
We also provide physical:
You can study this module on its own or use the credits you gain towards an Open University qualification.
TM355 is an option module in our:
Communications technology (TM355) starts once a year – in October.
It will next start in October 2026.
We expect it to start for the last time in October 2030.
As a student of The Open University, you should be aware of the content of the academic regulations, which are available on our Student Policies and Regulations website.
You must have passed one of the following modules:
You should understand the distinction between analogue and digital, and be familiar with:
You should also understand and be able to perform basic manipulation of algebraic terms and to read graphs with linear and logarithmic scales.
We recommend Communication and information technologies (TM255) as suitable preparation.
The OU strives to make all aspects of study accessible to everyone, and this Accessibility Statement outlines what studying TM355 involves. You should use this information to inform your study preparations and any discussions with us about how we can meet your needs.
To find out more about what kind of support and adjustments might be available, contact us or visit our Disability support website.
StartEndRegister byEngland fee
03 Oct 202630 Jun 202710 Sep 2026£2,044
Studying with The Open University can boost your employability. OU courses are recognised and respected by employers for their excellence and the commitment they take to complete. They also value the skills that students learn and can apply in the workplace.
Over 30,000 employers have used the OU to develop staff so far. If the module you’ve chosen is geared towards your job or developing your career, you could approach your employer to see if they will sponsor you by paying some or all of the fees.
You can pay part or all of your tuition fees upfront with a debit or credit card when you register for each module.
We accept American Express, Mastercard, Visa and Visa Electron.
Please note: your permanent address/domicile will affect your fee status and, therefore, the fees you are charged and any financial support available to you. The fee information provided here is valid for modules starting before 31 July 2027. Fees typically increase annually. For further information about the University's fee policy, visit our Fee Rules.
Level info