Wireless Networking

Bluetooth

2.4 GHz range (2.4-2.4835 GHz)

802.11ax (WiFi 6)

4x to 10x faster than existing Wi-Fi It is carefully designed to be maximally forward and backward compatible with 802.11a/b/g/n/ac devices. AP available 2018; clients available in 2019

Network radio ranges

902-928 MHz, 2.4-2.4835 GHz, 5-5.825 GHz, and others

Transaction (card emulation)

A device with a NFC chip can be used as debit card, credit card, library card, public transit pass card, hotel room keycard, office building access control card, airline ticket, personal health monitor, etc.

Near Field Communication (NFC)

A short-range, low-power, but slow communication technology between devices Effort-free (setup-free and convenient) but NFC can have two-way communication

ANT

ANT is a proprietary but open access oriented towards usage with sensors (mesh) sports and fitness sensor 2.4 GHz

Pairing (peer to peer)

Ad hoc peer-to-peer communication (exchanging photo, document, contact information, PayPal fund transfer, etc.) or quickly setup a Bluetooth or WiFi connection

Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

Also called the distributed coordination function CSMA/CA works to avoid collisions Coordinate nodes using DIFS (distributed coordination function's intraframe space) delay and backoff time (slot-time and random number)

Infrared Technologies

Broadcasts in single direction or all directions Advantages of infrared medium Inexpensive Difficult to intercept Not prone to RFI or EMI Disadvantages of infrared medium Does not penetrate walls Experiences interference from strong visible light

Independent basic service set (IBSS) topology

Consist of two or more stations in direct communication Peer-to-peer communication between WNICs on nodes Stations often added on impromptu basis

Extended service set (ESS) topology

Deploys one or more access points Enables more extensive area of service than the IBSS Network sizes range from small to large

Inter-Access Point Protocol (IAPP)

Enables mobile station to move among cells Encapsulates UDP and IP for roaming communications

802.11ac (WiFi 5)

Exclusively 5 GHz frequency range Transmission speeds > 1 Gbps mandatory 80 MHz (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation Adopted by new smartphones (HTC One is the first one, released in March 2013)

HiperLAN

High-performance radio local area network (EU) Transmits at up to 54 Mbps in the 5 GHz range Supports Data Encryption Standard (DES) Supports Quality of Service (QoS)

XBee

IEEE 802.15.4 standard designed for point-to-point and star communications at 250 Kbps

Thread

IPv6-based EEE 802.15.4 network and is related to 6LoWPAN (IPv6 over Low-Power Wireless Personal Area Networks) 2.4 GHz Mesh network 250 Kbps transmission rate IP-addressable (direct Internet and cloud access for every device)

Three influential developments related to wireless networks

Industrial, Scientific, Medical (ISM) band opened (1985) Telecommunications Act of 1996 IEEE 802.11 standard set (1997)

Priority-based access (or point coordination function)

Intended for time-sensitive communications Access point functions as point coordinator Point coordinator establishes contention-free period Method revolves around contention-free period (pollable, polling list, beacon frame)

Li-Fi (Light-Fidelity)

Li-Fi technology uses light waves instead of RF spectrum to communicate data Use LED light bulbs or potentially laser light

Sharing (read/write)

Like a QR code, getting information (or just a URL) of an item (for ads, coupons, etc.)

Wireless Hotspots

Locations that provide a public access point to users

802.11n (WiFi 4)

Offers transmission speeds over 600 Mbps (pure 5 GHz band) Operates over greater distances (up to 250 m outdoor) than 802.11a, 802.11b, and 802.11g Backward compatible to older 802.11a, 802.11b, and 802.11g networks

Wibree

Operate in 2.4 GHz band A subset of Bluetooth v4.0

802.11ah (Wi-Fi HaLow)

Operate in the 900 MHz band. Low energy consumption - allowing the creation of large groups of stations or sensors that cooperate to share signals, supporting the concept of the Internet of Things (IoT). Intended to be competitive with Bluetooth 5 with its low power consumption, but with a wider coverage range Data rates up to 347 Mbps

802.11a (WIFI 2)

Outlines speeds in 5 GHz frequency range Minimum speed: 6 Mbps Maximum speed: 54 Mbps Uses Orthogonal Frequency Division Multiplexing (OFDM)

802.11b (WIFI 1)

Outlines speeds in the 2.4 GHz frequency range Minimum speed: 1 Mbps Maximum speed: 11 Mbps Uses Direct Sequence Spread Spectrum (DSSS)

802.11ad

Promoted by Wireless Gigabit Alliance (WiGig) which was merged with the Wi-Fi Alliance in 2013 Operate in the 60 GHz spectrum. This frequency band has significantly different propagation characteristics than the 2.4 GHz and 5 GHz bands where Wi-Fi networks operate. The peak transmission rate of 802.11ad is 7 Gbps. TP-Link announced the world's first 802.11ad router in January 2016.

Two drawbacks of wire-based networking

Tangle of wires connecting computer and peripherals Cost of pulling wires through walls, ceilings, floors

WirelessHD

The WirelessHD Consortium serves to organize an industry-led standardization effort to define a next-generation wireless digital interface specification for consumer electronics and PC products. 60 GHz band (57-64)

wake time scheduling.

This enables APs to tell clients when to go to sleep and provides a schedule of when to wake. These are very short periods of time, but being able to sleep a bunch of short times will make a big difference on battery life.

Wireless NIC (WNIC)

Transceiver card, functions as transmitter and receiver, operates at physical and Data link layers, may be internal (PCI card) or external (USB key fob)

Radio Frequency Identification (RFID)

Use radio waves to track and identify objects (e.g., people, animals, shipment)

WiMAX

Worldwide Interoperability for Microwave Access called connection for "last mile" Connects home or office to wired network provider

NB-IoT

a Low Power Wide Area Network (LPWAN), narrowband, radio technology standard developed to enable a wide range of devices and services to be connected using cellular telecommunications bands

Roaming

ability to move wireless device across cells

Cell

broadcast area around single access point

Antenna

device radiates and receives radio waves Directional Antenna - sends radio waves one main direction Omnidirectional Antenna - sends radio waves in all directions

Asynchronous

discrete units with start and stop bit

Access Point

interfaces WNIC and cable network Examples: bridge, switch, router, and cell tower

Dedicated Short Range Communication (DSRC)

is a two-way short- to medium-range wireless communication capability that permits very high data transmission for use by Intelligent Transportations Systems vehicle safety and mobility applications. licensed band (5.9 GHz band) Priority for safety application

LoRaWAN

is a wireless technology for managing communication between LPWAN gateways and end-node devices. Star network

IEEE 802.11 group

most influential wireless standards -Includes 802.11a, b, g, n, ac Communication with 802.11 devices is non-proprietary Data Link and Physical

Z-Wave

proprietary: Zensys, Sigma Designs Unlicensed frequency band 800-900 MHz 30-40m range Mesh network over 1,700 products have been certified by the Z-Wave Alliance

Synchronous

signal has timing restrictions

Backscatter

the reflection of the radio waves from the reader (transceiver) striking the RFID tag (transponder) which stores unique identification information

OFDMA (Orthogonal frequency-division multiple access)

to improve overall spectral efficiency Multiple access This allows simultaneous low-data-rate transmission from several users. Improves battery life

Ultra-Wideband (UWB)

to operate at 3.1 - 10.6 GHz band Limited distance is the major disadvantage

Wireless Components

transceiver, access point, antenna

Zig Bee

very low power consumption 2.4 GHz Mesh network (help relay) Up to 65K devices LR-WPANs: Low-Rate Wireless Personal Area Networks

Wireless ad-hoc network

wireless mesh network or mobile ad hoc network (MANET), is a wireless network made up of nodes organized in a mesh topology. forwards messages on behalf of the other nodes and each node performs routing. Ad hoc networks can "self-heal", automatically re-routing around a node that has lost power