Metal Conducting Cables vs. Optical Cables

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2.1.3 Transmission Speed of Data

Bandwidth’ specifies the quantity of data a particular channel transmits and it is crucial to fully understand it in any form of communications. The bandwidth is fixed for a channeled. A general guideline highlights that a higher bandwidth will sup- port a higher information rate. As a particular transmission me- dium’s bandwidth is fixed, data transmission rate can be increased by adding more bits into one ‘band’. A tally of the number of changes of electronic states per second is referred to as a baud. For an instance, a copper cable of 1k baud changes the voltage 1000 times in one second. A crucial fact is it does not essentially mean that it just transmits 1000 data bits per se- cond. This is explainable by examining several mathematics equations, even though we will not probe into the concepts. A specific number of distinct signal levels L is referred to each baud or shift of signaling state in one second. For instance, the voltage levels of 0.5 V and 1.0 V. These distinctive levels can be represented by combinations of binary bits. For example 01 and 11 represent 0.5 V and 1.0 V respectively. A direct relationship exists for the the number of bits n for every baud: n = log 2 L Or: L = 2 n Thus, in this specific example, there are two bits n = 2 and four dissimilar levels L = 4 each one indicated as 00, 01, 10, and 11. Moreover, the data transmission rate or bit rate, counted in number of bits per second or bps might be expanded for a given fixed baud rate by utilizing more diverse signaling levels as more bits can be transmitted by every baud. Bandwidth 2.2 2.3 33 is a significant term in illustrating the data transmission rate that is supported by a particular channel. It denotes the band of fre- quencies that an electronic signal uses while disseminating data over the channel. Thus, when measuring the bandwidth of a specific channel, it is often measured in hertz Hz which de- picts the difference between the maximum frequency and the minimum frequency used. For instance, a phone channel trans- ferring voice data between a maximum frequency of 3 400 Hz and minimum frequency of 300 Hz has a bandwidth of 3.1 Khz. Hence to explain the correlation between a channel bandwidth and data transmission speed, SyQuest theorem points out that the bit rate R b of a channel of bandwidth H is:- R b = 2.H log 2 L Hypothetically, this is highest data transmission rate a channel is able to reach. A real communication channel may have lower bit rate than this due to several factors. Previously it has been discussed that utilizing more diverse levels will enable more bits to be transmitted by each one change of signaling state to enhance the efficiency of the transmission. On the other hand, having more distinct levels would press the signaling levels closer together. For instance, in the example mentioned earlier, each stage is 0.5 V. We utilize eight levels to represent four bits for every level instead of representing two bits. This way, we may lessen the division between the levels from 0.5 V to just 0.25 V. The most critical issue here is that signaling levels may overlap due to the noise. The noise level N relates to the mini- mum division between two levels before the noise causes errors to cross the border of the neighboring level. The equation below gives the maximum number of levels L, in which refers to the maximum or peak signal power level. 2.4 34 Generally, the maximum data transmission rate R b is directly proportional to peak signal power S, and inversely propositional to channel noise N. An idea communication system must deliv- er the best possible transmission rate with the least power con- sumption with minimum noise. With reference to the equation above, a fundamental theory about the speed of data transmis- sion has been attained.

2.1.4 Electromagnetic Interference

Wireless communications does have significant disadvantage which is EMI electromagnetic interference as the EMI impact is considerably more challenging than with wired cables. Here, wireless transmitting gadgets can drastically influence the ma- nipulation of some sensitive medical gadgets. As such, the im- pact of EMI is especially dangerous in medicinal services applications. Tikkanen 2005a, tikkanen 2009b, ho 2012 has explored different methods of managing the effects of EMI in healthcare services to guarantee reliability of the gadgets used. Some of the methods include using a suitable casing for medicinal instruments that can successfully shield the device from getting unwanted interference. A wide variety of compo- site materials may be useful to achieve this purpose. Metalized plastic materials are capable of being transformed into virtually any shape and possess the advantage of providing substantive shielding despite being light weighted. These qualities make them apt in housing numerous kinds of devices. There are three potential issues those results in EMI:- 2.5 35 ¾ source radiating noise, ¾ receiver grabbing noise, and ¾ Coupling channel between source and receiver. All wireless transmitting gadgets such as cellular phones and laptop computers are susceptible to EMI from proximate radiat- ing sources. Such interference initiates capacitive coupling where energy is stored up inside the circuit and hence, affecting the electronic circuitry. This generates a wavering electric field that may be capacitive coupled to adjacent gadgets. There are two major forms of EMI; continuous and transient interference, which may be a result of thunderstorms provoking Lightning Electromagnetic Pulse LEMP or swapping of high current cir- cuits. The continuous interference is initiated by emission of radiation in a consistent manner from nearby sources, for exam- ple, other medical devices or transmitting gadgets. Transient interference is intermittent, where sources radiates for a short time. These might be set off by thunderstorms initiating Light- ning Electromagnetic Pulse LEMP or turning on high current circuits. The International Electro Technical Commission IEC manages standard regulations regarding EMI while the Comite International Special des Perturbations Radio Electriques CISPR or the International Special Committee on Radio Inter- ference, manages concerns related to radio. The CE mark, which is often found on electronic items that include healthcare and medical equipment, denotes Conformite Europeenne or European Conformity. Items bearing the CE stamp proves the item conforms to the European Directives that oblige Elec- tromagnetic Compatibility EMC tests to be carried out to as- sure that a particular item fulfill the European Union EU directive 2004108ce prior to its legitimate release into the market in any component countries of the EU.