Multiplexing

Multiplexing

Multiplexing is a technique for carrying numerous signals over a single media that is illustrated at the physical layer of the open system interconnection (OSI) paradigm (Latafa, 2012). Signals sent through multiple communication channels are combined into a single output with high-speed signals. A 2-to-1 multiplexer, for example, has two input signals, an 8-to-1 multiplexer has eight input signals, and a 4-to-1 multiplexer has four input signals; all multiplexers have one output signal (Chaudhary, 2015). Multiplexing techniques include dense wavelength division multiplexing, time division multiplexing, and frequency division multiplexing, which are addressed more below.

Frequency Division Multiplexing (FDM)

Frequency Division Multiplexing (FDM) is the process of combining several signals for transmission over a single communication line. Different frequency is assigned to each data within the main channel. Signals to be transmitted must be analog in FDM thus all digital need to converted to analogue (Murray, 2015). FDM is used by Television Transmitters which uses frequency division multiplexing to broad cast different channels at a time, first generation cellular telephone uses it and also it is used for AM and FM radio broadcasting in which AM and FM radio stations use different carrier frequency.

Time Division Multiplexing (TDM)

Time Division Multiplexing (TDM) is a type of multiplexing technique which a user is allotted a particular time interval that frequently transfers by that user. Several users divide total time available in the channel. TDM system is suitable for digital signal multiplexing than analog. Signals are transmitted one by one therefore, transmission takes short time. Data rate capacities required by sending or receiving devices are smaller than data rate capacity of transmission medium (Ridha et al. 2015). There are two types of TDM; Synchronous and asynchronous TDM. Synchronous TDM, same time slot is given to each device to transmit data irrespective the devise has any information to transmit. Time slot remains empty if the device has no information to transfer. Asynchronous TDM, time slots are not fixed, speed of input lines can be greater than the capacity of the path. Transmission occurs in no definite order.

Dense Wavelength Division Multiplexing (DWDM)

Dense wavelength division multiplexing (DWDM) is a technique where data is put from different sources onto fiber optic. Each signal is carried on separate light wavelength. An advantage of DWDM is the ability to provide unlimited transmission capacity. It has fast and dynamic network connection with the ability to provide high services for users (Lafata et al. 2012). DWDM can support time division multiplexing and also formatting of data an example is, ATM. Changes in demand, can also increase its capacity of equipment or data.

Open System Interconnection

Open System Interconnection, is the communication of application over a single large network. It is designed to facilitate communication between hardware and software devices. There are four elements of OSI; Association control service element, in preparation for communication it creates relationships between two application (Murray et al. 2010). Remote operations service element is a service that allows interaction among organizations in a distributed application, Reliable transfer service element it provides a user an application element which has a reliable means of transferring messages, Commitment, concurrence, and recovery service element multiple application organs dialogues are coordinated by this element.

Conclusion;

A multiplexer is a building block in many digital systems; it is a combination of circuit with more than one input but with a single output switch. A devise is shared through multiple signals (Frisch, 2013). Open system interconnection (OSI) layers can implement multiplexing.

REFERENCES;

Murray, D., Dixon, M., & Koziniec, T. (2010, October). An experimental comparison of routing protocols in multi hop ad hoc networks. In Telecommunication Networks and Applications Conference (ATNAC), 2010 Australasian (pp. 159-164). IEEE.

Bouallegue, M., Benfradj, H., Raoof, K., & Ridha, B. (2015). Design and implementation of new routing strategy for enhanced energy efficient in wsn. International Journal of Computer Networks and Communications (IJCNC), 7(4).

Chaudhary, M. (2015). Wireless Sensor Networks: A Comprehensive Comparison of Routing Protocols and Energy Efficient Techniques.

Lafata, P., Jares, P., & Vodrazka, J. (2012, July). Increasing the transmission capacity of digital subscriber lines. In Telecommunications and Signal Processing (TSP), 2012 35th International Conference on (pp. 292-296). IEEE.

Frisch, I. T., Malek, M., & Panwar, S. S. (Eds.). (2013). Network management and Control (Vol. 2). Springer Science & Business Media.