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Md Arafat Hossain

Lecture 1: Communication Networks and Services. Md Arafat Hossain. Department of Electrical and Electronic Engineering, Khulna University of Engineering and Technology, Khulna, BANGLADESH. Introduction. What is a communication networks?.

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Md Arafat Hossain

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  1. Lecture 1: Communication Networks and Services Md Arafat Hossain Department of Electrical and Electronic Engineering, Khulna University of Engineering and Technology, Khulna, BANGLADESH

  2. Introduction What is a communication networks? A communication network (or simply network) consists of an interconnection of a number of routers made up of intelligent processors. Route data through the network Purposes • Serve as a shared resource • Efficient data exchange • Provide framework to support new application and services

  3. Different types wireless networks Some commonly used networks in telemedicine applications and explain why they are suitable for specific situations • Bluetooth • IR • Wi-Fi • ZigBee • Cellular Networks • WiMAX (fixed) • LMDS

  4. Different types wireless networks • Invented in 1994 by Ericsson. Later developed with a larger company Bluetooth Special Interests Group, or "SIG. • Provides short range coverage primarily for mobile devices connected in an ad hoc network called ‘piconet’ within a room. • Bluetooth operates at frequencies between 2402 and 2480 MHz, or 2400 and 2483.5 MHz including guard bands 2 MHz wide at the bottom end and 3.5 MHz wide at the top. • IEEE standardized Bluetooth as IEEE 802.15.1, but no longer maintains the standard. The Bluetooth SIG oversees development of the specification, manages the qualification program, and protects the trademarks. • Bluetooth • Bluetooth divides transmitted data into packets, and transmits each packet on one of 79 designated Bluetooth channels(Each channel 1 MHz). Bluetooth Low Energy uses 2 MHz spacing, which accommodates 40 channels

  5. Different types wireless networks Useful for small wearable biosensors due to low power • Bluetooth applications CMS50D-BT Bluetooth Pulse Oximeter [2] notebook internal Bluetooth card  Bluetooth mobile phone headset Bluetooth USB dongle • Key selling points are low cost requiring simple circuitry and low power consumption. [2] Contec Cms50d-Bt FDA Telemedicine Finger Pluse Bluetooth APP Fingertip SpO2 Oximeter

  6. Different types wireless networks • Bluetooth 1.1 • Ratified as IEEE Standard 802.15.1 (2002) • Received Signal Strength Indicator (RSSI) • Bluetooth 1.2 • Faster connection • Adaptive frequency-hopping spread spectrum • Higher transmission speeds (721 kbps) • Extended Synchronous Connections (eSCO), • Bluetooth 2.0 + EDR  (2004) • Enhanced Data Rate (EDR) for faster data transfer (3 Mbps)  • Bluetooth 2.1 + EDR (2007) • Secure simple pairing (SSP): this improves the pairing experience for Bluetooth devices [1] https://en.wikipedia.org/wiki/Bluetooth

  7. Different types wireless networks • Bluetooth 3.0 + HS (2009) • Data transfer speeds of up to 24 Mbps (theoretically) • Bluetooth 4.0 + LE (2010) • Includes Classic Bluetooth, Bluetooth high speed and Bluetooth Low Energy (BLE) protocols • Bluetooth 4.1 (2013) • An incremental software update: Increased co-existence support for LTE, bulk data exchange etc. • Bluetooth 4.2 (2014) • Introduces features for the IoT: Low Energy Secure Connection, Link Layer Privacy, Internet Protocol Support Profile (IPSP) • Bluetooth 5 (2016) (“NOT 5.0”) • Bluetooth 5 provides, for BLE, options that can double the speed (2 Mbps burst) at the expense of range, or up to fourfold the range at the expense of data rate, and eightfold the data broadcasting capacity of transmissions, by increasing the packet lengths Few example device: Samsung Galaxy S8, iPhone 8, 8 Plus, iPhone X [1] https://en.wikipedia.org/wiki/Bluetooth

  8. Different types wireless networks • Infra-red (IR) Can not penetrate through wall Regulated by Infrared Data Association (IrDA): IR transmitter near-infrared or IR-A is used in night vision applications wireless communications usually use short-wavelength infrared (IR-B). .. long range optical communications IR receiver Si

  9. Different types wireless networks • Infra-red (IR) • Can not penetrate through wall • Requires direct LOS and the transmitter must be aligned fairly close to the centre of the sensor with only +/- 15º offset possible Although current IrDA compatible devices support only up to 16 Mbps, the introduction of Giga-IR offers a theoretical speed of up to 1 Gbps. It is often used in small ECG fragment transmission. IR transmitter IR receiver Si

  10. Different types wireless networks • Wireless Local Area Network (WLAN) and WiFi Unlike Bluetooth and IR, WLAN requires some efforts in setting up initial configurations before a communication link can be established. Mobile Desktop with PCI 802.11 LAN card Network connectivity to the legacy wired LAN Laptop with PCMCIA 802.11 LAN card Access Point • Provides network connectivity over wireless media • An Access Point (AP) is installed to act as Bridge between Wireless and Wired Network • The AP is connected to wired network and is equipped with antennae to provide wireless connectivity

  11. Range (Distance between Access Point and WLAN client) depends on structural hindrances and RF gain of the antenna at the Access Point. So varies for indoor or outdoor operation 50 to 300 m. • To service larger areas, multiple APs may be installed with a 20-30% overlap • A client is always associated with one AP and when the client moves closer to another AP, it associates with the new AP (Hand-Off) • Three flavors: based on the specifications for PHY & MAC layer • 802.11b (1, 2, 5.5 and 11 Mbps data rates in the 2.4 GHz ISM) • 802.11a (54 Mbps @ 5 GHz UNII band ) • 802.11g (54 Mbps on the 2.4 GHz band) • PHY:how raw data bits are transmitted over the air • MAC: Provides addressing and channel access control procedures that allow several devices to communicate with a single Access Point

  12. Different types wireless networks • ZigBee • Small digital devices for WPAN complying IEEE802.15.4 • Easy to implement and very low power consumption, low cost (transreceiver less than 1 U$) • Primarily used for wireless data controlling and monitoring • No global standard for operating f, 686 MHz (Europe), 915 MHz (USA), 950 MHz (Japan) and 2.4 GHz (other parts if the world) • Regularly used in safety devices e.g. smoke detector, air con control etc, Also used in BAN. • Communication Net can be served with ZigBee Co-cordinator and effective used to relay data between device

  13. Different types wireless networks • Cellular Networks • The mobile phone network we are using everyday

  14. Cellular Networks

  15. Broadband Wireless Access (BWA) Provides high speed wireless Internet access or computer networking access over a wide area. The term comprises both fixed and mobile broadband. Broadband: download >25 Mbits and upload >3 Mbits (FCC) • Ultra high speed – support diverse variety of services • fc can be few GHz to 40 GHz (depends on the local regulation ) • Technologies used include Local Multipoint Distribution Service (LMDS) and Multichannel Multipoint Distribution Service (MMDS), as well as heavy use of the industrial, scientific and medical (ISM) radio bands and one particular access technology was standardized by IEEE 802.16, with products known as WiMAX • LMDS is a prevalent WBA development, can support data over 512 Mbps. The properties of LMDS make it particularly suited for telemedicine backbone support. • main trunk line for interconnecting different LANs as well as equipment together over a large area

  16. Different types wireless networks • Satellite Network • Comsat (communication satellite) serve as a point-to-point microwave radio relay that provides a radio link between two earth sations. • Used in Wide Area Network (WAN) • Very reliable and high speed comm link – suitable for remote robotic surgery

  17. Different types wireless networks • Licensed and unlicensed frequency bands • Some net operates in licensed band while many others operates in unlicensed band and share with many users. • How they can affect in telemedicine? • No implementation delay and cost in unlicensed band. Accessed by many devices so stay at a risk of security braches and interference. • Unlicensed • Vs • Interference protection and guaranteed bandwidth availability in licensed band. • Licensed

  18. Comparison: Different types wireless networks

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