Communication Systems Core Topic 3 Communication Systems Communication

Communication Systems Core Topic 3

Communication Systems �Communication systems allow people and systems to share and exchange information electronically. We do this through transmitting and receiving hardware and software over a network. �Each device on a network is called a node and each message is encoded into a suitable form to be transmitted over either a wired or wireless medium.

Communication Systems �During its travels a message will follow a variety of paths through many different networks and connection devices. For example it typically include… • Switches making decisions based on MAC addresses AND • Routers using IP addresses for guidance

Communication Systems �Eventually a message will arrive at the receiver who decodes the message at its destination. �The network could be a local area network (LAN), a wide area network (WAN), the internet, an intranet, extranet or any combination of the above.

Communication Systems

Communication Systems �Successful communication requires components to agree on a set of rules. We call this a protocol. �Agreeing and establishing communication according to protocols must occur prior to data being transmitted or received. This is called handshaking. For example. . .

Communication Systems �Protocols are classified according to the layer or level in which they operate. This can be seen in the Open Systems Interconnection model or the OSI. The OSI looks like this…

Communication Systems

Communication Systems Due to the complexity of the OSI the IPT syllabus will condense these layers to 3 – Application, Communication and Control & Transmission.

Communication Systems As messages pass through the interface they are encoded down through the protocols until they are transmitted. The message is progressively encoded using the protocol/s operating at each level.

Communication Systems Equally the message is progressively decoded by each protocol in turn as it ascends through each level of the protocol stack back towards the destination from the receiver at the transmission level.

Communication Systems Definitions… �Node – A terminal or point on a network: e. g. a PC or printer. �Protocol – A set of rules. �Handshaking – The agreement on protocol prior to information being sent.

Communication Systems In this topic we will look at… �Characteristics of Comms Systems �Examples of Comms Systems �Network Communication Concepts �Network Hardware �Network Software �Issues related to Comms Systems