Chapter 5.pdf

CCCN 422 Wireless Communication Networks Dr. Mohammed Balfaqih Assistant Professor [email protected] @modditto Lecture Outline ▪ Wireless Local and Personal Area Networks • • • • • • IEEE 802 Architecture IEEE 802.11 Architecture and Services IEEE 802.11 Medium Access Control IEEE 802.11 Phys...

CCCN 422 Wireless Communication Networks Dr. Mohammed Balfaqih Assistant Professor [email protected] @modditto Lecture Outline ▪ Wireless Local and Personal Area Networks • • • • • • IEEE 802 Architecture IEEE 802.11 Architecture and Services IEEE 802.11 Medium Access Control IEEE 802.11 Physical Layer Other IEEE 802.11 Standards Bluetooth and Zigbee Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Overview and Motivations ▪ Introduction • Wireless LANs (WLANs) - Indispensable adjunct to wired LANs Wireless devices use WLANs Example of Single-Cell Wireless LAN Configuration As their only source of connectivity Or to replace cellular coverage • Simple WLAN configuration - There is a backbone wired LAN User modules include workstations, servers, devices Control module (CM) interfaces to WLAN Providing bridge or router functionality May have control logic to regulate access May provide wireless connectivity to other wired networks • Multiple-cell wireless LAN - Multiple CMs connected by a wired LAN - Creates many issues for balancing cell loading and providing best connections for Ums Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Overview and Motivations Example of Multiple-Cell Wireless LAN Configuration Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Overview and Motivations ▪ Ad Hoc Networking • Temporary peer-to-peer network set up to meet immediate need - Peer-to-peer, no centralized server Maybe a temporary network Wireless connectivity provided by WLAN or Bluetooth, ZigBee, etc. • Example: - Group of employees with laptops convene for a meeting; employees link computers in a temporary network for duration of meeting Ad Hoc Wireless LAN Configuration Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Overview and Motivations ▪ Wireless LAN motivations • Cellular data offloading - WLANs may provide higher data rates and more available capacity Cellular providers may encourage this to offload demand on their networks • Sync/file transfer - Avoid use of cables • Internet access • Multimedia streaming ▪ Wireless LAN Requirements • • • • • Throughput Number of nodes Connection to backbone LAN Service area Battery power consumption • • • • • Transmission robustness and security Collocated network operation License-free operation Handoff/roaming Dynamic configuration Comparisons between WLANs, wired LANs, and mobile data networks can be visualized with Kiviat graphs. Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Overview and Motivations Kiviat Graphs for Data Networks Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802 Architecture ▪ Protocol Architecture • Developed by the IEEE 802.11 working group • Uses layering of protocols • LAN protocols focus on the lower layers of the OSI model - Figure 11.5 relates OSI with 802.11 Called the IEEE 802 reference model Dr. Mohammed Balfaqih IEEE 802 Protocol Layers Compared to OSI Model IEEE 802 Architecture ▪ Wireless LAN physical layer • Multi-cell arrangement • Transmission Issues - No licensing needed – Four microwave bands 902-928 MHz 2.4-2.5 GHz 5.725-5.875 GHz 58-64 GHz (60-GHz mmWave bands) Higher capacity Less competition More expensive equipment - Spread spectrum DSSS CDMA or OFDM Over 1 Gbps possible with OFDM, channel bonding, and MIMO Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802 Architecture • Functions of physical layer: - Encoding/decoding of signals Preamble generation/removal (for synchronization) Bit transmission/reception Includes specification of the transmission medium • Sublayers - Physical medium dependent sublayer (PMD) Transmitting and receiving user data through a wireless medium - Physical layer convergence procedure (PLCP) Mapping 802.11 MAC layer protocol data units (MPDUs) into a framing format Sending and receiving between stations using same PMD sublayer • Functions of medium access control (MAC) layer: - On transmission, assemble data into a frame with address and error detection fields On reception, disassemble frame and perform address recognition and error detection Govern access to the LAN transmission medium • Functions of logical link control (LLC) Layer: - Provide an interface to higher layers and perform flow and error control Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802 Architecture IEEE 802 Protocols in Context Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802 Architecture ▪ Separation of LLC and MAC • The logic required to manage access to a shared-access medium not found in traditional layer 2 data link control • For the same LLC, several MAC options may be provided ▪ MAC Frame Format • MAC control - Contains Mac protocol information • Destination MAC address - Destination physical attachment point • Source MAC address - Source physical attachment point • CRC - Cyclic redundancy check Dr. Mohammed Balfaqih LLC PDU in a Generic MAC Frame Format IEEE 802 Architecture ▪ Logical Link Control • Characteristics of LLC not shared by other control protocols: - Must support multi-access, shared-medium nature of the link - Relieved of some details of link access by MAC layer ▪ LLC Services • Unacknowledged connectionless service - No flow- and error-control mechanisms - Data delivery not guaranteed • Connection-mode service - Logical connection set up between two users - Flow- and error-control provided • Acknowledged connectionless service - Cross between previous two - Datagrams acknowledged - No prior logical setup Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services ▪ IEEE 802.11 • Started in 1990 - MAC and physical medium specifications • Wi-Fi Alliance - Industry consortium - Creates test suites to certify interoperability of products May identify a subset of the standard for certification - Concerned with a range of market areas for WLANs • IEEE 802.11 has an ever expanding list of standards Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services ▪ IEEE 802.11 Architecture • Distribution system (DS) • Access point (AP) • Basic service set (BSS) - Stations competing for access to shared wireless medium - Isolated or connected to backbone DS through AP • Extended service set (ESS) - Two or more basic service sets interconnected by DS ▪ Distribution of Messages Within a DS • Distribution service - Used to exchange MAC frames from station in one BSS to station in another BSS • Integration service - Transfer of data between station on IEEE 802.11 LAN and station on integrated IEEE 802.x LAN Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Architecture and Services ▪ Transition Types Based On Mobility • No transition - Stationary or moves only within BSS • BSS transition - Station moving from one BSS to another BSS in same ESS • ESS transition - Station moving from BSS in one ESS to BSS within another ESS ▪ Association-Related Services • Association - Establishes initial association between station and AP • Reassociation - Enables transfer of association from one AP to another, allowing station to move from one BSS to another • Disassociation - Association termination notice from station or AP Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ MAC layer covers three functional areas: • Reliable data delivery • Access control • Security ▪ Reliable Data Delivery • More efficient to deal with errors at the MAC level than higher layer (such as TCP) • Frame exchange protocol - Source station transmits data - Destination responds with acknowledgment (ACK) - If source doesn‘t receive ACK, it retransmits frame • Four frame exchange - Source issues request to send (RTS) Destination responds with clear to send (CTS) Source transmits data Destination responds with ACK Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Access control • Centralized and decentralized mechanisms together - Distributed foundation wireless MAC (DFWMAC) • Distributed coordination function (DCF) - Decentralized • Point coordination function (PCF) - Centralized • Both are available to the LLC layer Dr. Mohammed Balfaqih IEEE 802.11 Protocol Architecture IEEE 802.11 Medium Access Control IEEE 802.11 Medium Access Control Logic ▪ Distributed coordination function • Decentralized • Carrier sense multiple access (CSMA) Listen to the medium If idle, then transmit If not, wait a random time If busy again, expand the mean waiting time, randomly wait, and try again. Binary exponential backoff describes this procedure The backoff is the waiting process Mean random waiting times get exponentially larger By a factor of 2 each time, hence the term binary. This process responds to heavy loads Since nodes do not know the loads of other nodes trying to send. Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Interframe Space (IFS) Values • Short IFS (SIFS) - Shortest IFS - Used for immediate response actions • Point coordination function IFS (PIFS) - Midlength IFS - Used by centralized controller in PCF scheme when using polls • Distributed coordination function IFS (DIFS) - Longest IFS - Used as minimum delay of asynchronous frames contending for access ▪ IFS Usage • SIFS: Acknowledgment (ACK), Clear to send (CTS), Poll response. • PIFS: Used by centralized controller in issuing polls, Takes precedence over normal contention traffic • DIFS: Used for all ordinary asynchronous traffic Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Point coordination function • Centralized control • Point coordinator polls devices - To give them permission to send - On a schedule the point coordinator determines • The superframe allows time to be shared between DCF and PCF - PCF starts the superframe and can only use a certain part of the superframe time Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ MAC Frame Fields • • • • • • Frame Control – frame type, control information Duration/connection ID – channel allocation time Addresses – context dependent, types include source and destination Sequence control – numbering and reassembly Frame body – MSDU or fragment of MSDU Frame check sequence – 32-bit CRC Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Frame Control Fields • • • • • • • • • • Protocol version – 802.11 version Type – control, management, or data Subtype – identifies function of frame To DS – 1 if destined for DS From DS – 1 if leaving DS More fragments – 1 if fragments follow Retry – 1 if retransmission of previous frame Power management – 1 if transmitting station is in sleep mode More data – Indicates that station has more data to send WEP – 1 if Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA) is implemented • Order – 1 if any data frame is sent using the Strictly Ordered service Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Control Frame Subtypes • • • • • • Power save – poll (PS-Poll) Request to send (RTS) Clear to send (CTS) Acknowledgment Contention-free (CF)-end CF-end + CF-ack ▪ Data Frame Subtypes • Data-carrying frames - Data Data + CF-Ack Data + CF-Poll Data + CF-Ack + CF-Poll - Null Function CF-Ack CF-Poll CF-Ack + CF-Poll • Other subtypes (don’t carry user data) Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 Medium Access Control ▪ Management Frame Subtypes • Association request • Association response • Reassociation request • Reassociation response • Probe request • Probe response • Beacon • Announcement traffic indication message • Dissociation • Authentication • Deauthentication ▪ Authentication • Open system authentication: Exchange of identities, no security benefits • Shared Key authentication: Shared Key assures authentication Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer IEEE 802.11 Physical Layer Standards Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer ▪ IEEE 802.11a AND IEEE 802.11b • IEEE 802.11b - DSSS - Provides data rates of 5.5 and 11 Mbps - Complementary code keying (CCK) and packet binary convolution coding (PBCC) modulation schemes - First standard to make Wi-Fi become popular • IEEE 802.11a - Makes use of 5-GHz band Provides rates of 6, 9 , 12, 18, 24, 36, 48, 54 Mbps Uses orthogonal frequency division multiplexing (OFDM) Subcarrier modulated using BPSK, QPSK, 16-QAM or 64-QAM Never became popular, but its formats and channel schemes are used for later releases of 802.11 Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer IEEE 802 Physical-Level Protocol Data Units Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer IEEE 802.11a Channel Scheme Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer • IEEE 802.11g - Extended rates up to 54 Mbps in 2.4-GHz band - Continued and extended PBCC from 802.11b that used DSSS Rates up to 33 Mbps - Also used OFDM for rates up to 54 Mbps Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer • IEEE 802.11n - Operates in both 2.4-GHz and 5-GHz bands - MIMO Multiple parallel streams (up to 4 × 4), beamforming, or diversity - Radio transmission schemes - Channel bonding to combine two 20 MHz channels From 48 subcarriers per 20 MHz to 108 carriers per 40 MHz (2.25 times increase in available bandwidth) Can only use 20 MHz channels if other nodes are active Shorter 400 ns guard band (11% increase in data rate) Higher coding rate of 5/6 (11% increase) 150 Mbps per 40 MHz, 600 Mbps for 4 parallel streams MAC enhancements Reduce header bits, backoffs, and IFS times Block acknowledgements: One ACK to cover multiple packets Frame aggregation Three forms MSDUs come down from the LLC layer, MPDUs come from the MAC layer A-MSDU aggregation – shared PHY and MAC headers and FCS A-MPDU aggregation – shared PHY header Still keep separate MAC headers, to less header reduction But not as much to retransmit if there is an error A-MPDU and A-MSDU aggregation – balances the two Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.11 physical layer Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Other IEEE 802.11 Standards ▪ Gigabit wi-fi • 802.11ac - Up to 3.2 Gbps 5-GHz only operation Up to 8 × 8 MIMO Up to 160 MHz (8 × 20 MHz channels) Special RTS/CTS to check for legacy devices - Up to 256 QAM - Multiuser MIMO Simultaneous beams to multiple stations Advanced channel measurements - Larger frame size - A-MDPU is required Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Other IEEE 802.11 Standards IEEE 802.11 Performance Factors Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Other IEEE 802.11 Standards RTS/CTS Enhanced with Bandwidth Signaling Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Other IEEE 802.11 Standards 5 GHz 802.11ac Channel Allocations Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Other IEEE 802.11 Standards ▪ Gigabit wi-fi • 802.11ad - WiGig - Up to 7 Gbps Replacement of wires for video to TVs and projectors - Uses 60-GHz bands Called millimeter waves (mmWave) Fewer devices operate in these bands Higher free space loss Poor penetration of objects Likely only useful in a single room - Adaptive beamforming and high gain directional antennas Can even find reflections when direct path is obstructed - Four modulation and coding schemes - Personal BSS so devices can talk directly Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.15 • Wireless Personal Area Networks – Short-range communication – Low-cost, low-energy to provide long battery life • Several standards have been provided • We focus on 802.15 technologies – Other viable WPAN alternatives exist Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Internet of Things • Key application area for short-range communications • Future Internet – Large numbers of wirelessly connected objects – Interactions between the physical world and computing, digital content, analysis, and services. – Called the Internet of Things • And many other “Internet of …” titles – Useful for health and fitness, healthcare, home monitoring and automation, energy savings, farming, environmental monitoring, security, surveillance, education, and many others. • Machine-to-machine communications (MTM, M2M, D2D, etc.), also machinetype communications (MTC) – Devices working together for data analysis and automated control Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth • • • • • Universal short-range wireless capability Uses 2.4-GHz band Available globally for unlicensed users Devices within 10 m can share up to 2.1 Mbps or 24 Mbps of capacity Supports open-ended list of applications – Data, audio, graphics, video • Started as IEEE 802.15.1 – New standards come from the Bluetooth Special Interest Group (Bluetooth SIG) • Industry consortium – Bluetooth 2.0, 2.1, 3.0, and 4.0 Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth Application Areas • Data and voice access points – Real-time voice and data transmissions • Cable replacement – Eliminates need for numerous cable attachments for connection • Ad hoc networking – Device with Bluetooth radio can establish connection with another when in range ▪ Top uses of Bluetooth • • • • • Mobile handsets • Wireless controllers for video game consoles Voice handsets • Cars Stereo headsets and speakers • Machine-to-machine applications: credit-card readers, industrial automation, etc. PCs and tablets Human interface devices, such as mice and keyboards Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth Standards Documents • Core specifications – Details of various layers of Bluetooth protocol architecture • Profile specifications – Use of Bluetooth technology to support various applications • We first focus on – 2.1 Basic/Enhanced Data Rate (BR/EDR) • Later standards – 3.0 Alternative MAC/PHY (AMP) – 4.0 Bluetooth Smart (Bluetooth Low Energy) Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Protocol Architecture Dr. Mohammed Balfaqih 12.1 Bluetooth Protocol Stack CCCN 422: Wireless Communication Networks Protocol Architecture • Bluetooth is a layered protocol architecture – Core protocols – Cable replacement and telephony control protocols – Adopted protocols • Core protocols – – – – – Radio Baseband Link manager protocol (LMP) Logical link control and adaptation protocol (L2CAP) Service discovery protocol (SDP) • Cable replacement protocol – RFCOMM • Telephony control protocol – Telephony control specification – binary (TCS BIN) • Adopted protocols - PPP Dr. Mohammed Balfaqih - TCP/UDP/IP - OBEX - WAE/WAP CCCN 422: Wireless Communication Networks Profiles • Over 40 different profiles are defined in Bluetooth documents – Only subsets of Bluetooth protocols are required – Reduces costs of specialized devices • All Bluetooth nodes support the Generic Access Profile • Profiles may depend on other profiles – Example: File Transfer Profile • Transfer of directories, files, documents, images, and streaming media formats • Depends on the Generic Object File Exchange, Serial Port, and Generic Access Profiles. • Interfaces with L2CAP and RFCOMM protocols Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Piconets and Scatternets • Piconet – Basic unit of Bluetooth networking – Master and one to seven slave devices – Master determines channel and phase Figure 12.2 Master/Slave Relationships Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Piconets and Scatternets • Scatternet – Device in one piconet may exist as master or slave in another piconet – Allows many devices to share same area – Makes efficient use of bandwidth Dr. Mohammed Balfaqih Figure 12.3 Wireless Network Configurations CCCN 422: Wireless Communication Networks Radio Specification • Classes of transmitters – Class 1: Outputs 100 mW for maximum range • Power control mandatory • Provides greatest distance – Class 2: Outputs 2.4 mW at maximum • Power control optional – Class 3: Nominal output is 1 mW • Lowest power Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Frequency Hopping in Bluetooth • Provides resistance to interference and multipath effects • Provides a form of multiple access among co-located devices in different piconets • Total bandwidth divided into 1MHz physical channels • FH occurs by jumping from one channel to another in pseudorandom sequence • Hopping sequence shared with all devices on piconet • Piconet access: – Bluetooth devices use time division duplex (TDD) – Access technique is TDMA – FH-TDD-TDMA Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Frequency Hopping in Bluetooth 9.2 FREQUENCY HOPPING EXAMPLE Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Frequency Hopping in Bluetooth 12.4 FREQUENCY-HOP TIME-DIVISION DUPLEX Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Frequency Hopping in Bluetooth 12.5 EXAMPLES OF MULTISLOT PACKETS Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Physical Links between Master and Slave • Synchronous connection oriented (SCO) – Allocates fixed bandwidth between point-to-point connection of master and slave – Master maintains link using reserved slots – Master can support three simultaneous links • Asynchronous connectionless (ACL) – Point-to-multipoint link between master and all slaves – Only single ACL link can exist • Extended Synchronous connection oriented (eSCO) – Reserves slots just like SCO – But these can be asymmetric – Retransmissions are supported Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth Packet Fields Dr. Mohammed Balfaqih 12.6 BLUETOOTH BASEBAND FORMATS CCCN 422: Wireless Communication Networks Bluetooth Packet Fields • Access code: used for timing synchronization, offset compensation, paging, and inquiry. It includes three types; - Channel access code (CAC) – identifies a piconet. Device access code (DAC) – used for paging and subsequent responses. Inquiry access code (IAC) – used for inquiry purposes. • Header: used to identify packet type and carry protocol control information. It includes the following fields; - AM_ADDR – contains “active mode” address of one of the slaves Type – identifies type of packet Flow – 1-bit flow control ARQN – 1-bit acknowledgment SEQN – 1-bit sequential numbering schemes Header error control (HEC) – 8-bit error detection code Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth Packet Fields • Payload: contains user voice or data and payload header, if present. It includes the following format; - Payload header L_CH field – identifies logical channel Flow field – used to control flow at L2CAP level Length field – number of bytes of data - Payload body – contains user data CRC – 16-bit CRC code Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Logical Channels • • • • • Link control (LC) Link manager (LM) User asynchronous (UA) User isochronous (UI) Use synchronous (US) • Link manager - Manages various aspects of the radio link between a master and a slave. - Involves the exchange LMP PDUs (protocol data units) - Procedures defined for LMP are grouped into 24 functional areas, which include Authentication Pairing Encryption Dr. Mohammed Balfaqih Clock offset request Switch master/slave Name request Hold or park or sniff mode CCCN 422: Wireless Communication Networks Link Manager • Manages various aspects of the radio link between a master and a slave. • Involves the exchange LMP PDUs (protocol data units) • Procedures defined for LMP are grouped into 24 functional areas, which include - Authentication Pairing Encryption Clock offset request Switch master/slave Name request Hold or park or sniff mode Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Logical link control and adaptation protocol (L2CAP) • • • • Provides a link-layer protocol between entities with a number of services Relies on lower layer for flow and error control Makes use of ACL links, does not support SCO links Provides two alternative services to upper-layer protocols – Connection service – Connection-mode service Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks L2CAP Logical Channels • Connectionless – Supports connectionless service – Each channel is unidirectional – Used from master to multiple slaves • Connection-oriented – Supports connection-oriented service – Each channel is bidirectional • Signaling – Provides for exchange of signaling messages between L2CAP entities Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Flow Specification Parameters • • • • • • Service type Token rate (bytes/second) Token bucket size (bytes) Peak bandwidth (bytes/second) Latency (microseconds) Delay variation (microseconds) Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth High Speed • • • • Bluetooth 3.0+HS Up to 24 Mbps New controller compliant with 2007 version of IEEE 802.11 Known as Alternative MAC/PHY (AMP) – Optional capability • Bluetooth radio still used for device discovery, association, setup, etc. • Allows more power efficient Bluetooth modes to be used, except when higher data rates are needed Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Bluetooth Smart • • • • Bluetooth 4.0 Previously known as Bluetooth Low Energy An intelligent, power-friendly version of Bluetooth Can run long periods of time on a single battery – Or scavenge for energy • Also communicates with other Bluetooth-enabled devices – Legacy Bluetooth devices or Bluetooth-enabled smartphones – Great feature • Possible successful technology for the Internet of Things – For example, health monitoring devices can easily integrate with existing smartphones Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks IEEE 802.15 • After 802.15.1, work went two directions • 802.15.3: Higher data rates than 802.15.1, But still low cost, low power compared to 802.11 • 802.15.4: Very low cost, very low power compared to 802.15.1 Dr. Mohammed Balfaqih Figure 12.10 shows relative distances and rates CCCN 422: Wireless Communication Networks ZigBee • • • • Extends IEEE 802.15.4 standards Low data rate, long battery life, secure networking Data rates 20 to 250 kbps Operates in ISM bands – 868 MHz (Europe), 915 MHz (USA and Australia), 2.4 GHz (worldwide) • Quick wake from sleep – 30 ms or less compared to Bluetooth which can be up to 3 sec. – ZigBee nodes can sleep most of the time. Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee • ZigBee complements the IEEE 802.15.4 standard by adding four main components – Network layer provides routing – Application support sublayer supports specialized services. – ZigBee device objects (ZDOs) are the most significant improvement • Keep device roles, manage requests to join the network, discover devices, and manage security. – Manufacturer-defined application objects allow customization. Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee 12.11 ZIGBEE ARCHITECTURE Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee • Star, tree, or general mesh network structures • ZigBee Coordinator – Creates, controls, and maintains the network – Only one coordinator in the network – Maintains network information, such as security keys • ZigBee Router – Can pass data to other ZigBee devices • ZigBee End Device – – – – Only enough functionality to talk to a router or coordinator Cannot relay information Sleeps most of the time Less expensive to manufacture Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee Network • Star, tree, or general mesh network structures • ZigBee Coordinator – Creates, controls, and maintains the network – Only one coordinator in the network – Maintains network information, such as security keys • ZigBee Router – Can pass data to other ZigBee devices • ZigBee End Device – – – – Only enough functionality to talk to a router or coordinator Cannot relay information Sleeps most of the time Less expensive to manufacture Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee alliance • Industry consortium • Maintains and publishes the ZigBee standard – ZigBee specifications in 2004 – ZigBee PRO completed in 2007 • Enhanced ZigBee • Profile 1 – home and light commercial use • Profile 2 – more features such as multicasting and higher security • Application profiles – Allow vendors to create interoperable products if they implement the same profile Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks ZigBee alliance • • • • • • • • • • • ZigBee Building Automation (Efficient commercial spaces) ZigBee Health Care (Health and fitness monitoring) ZigBee Home Automation (Smart homes) ZigBee Input Device (Easy-to-use touchpads, mice, keyboards, wands) ZigBee Light Link (LED lighting control) ZigBee Network Devices (Assist and expand ZigBee networks) ZigBee Retail Services (Smarter shopping) ZigBee Remote Control (Advanced remote controls) ZigBee Smart Energy 1.1 (Home energy savings) ZigBee Smart Energy Profile 2 (IP-based home energy management) ZigBee Telecom Services (Value-added services) Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks Thank you Dr. Mohammed Balfaqih CCCN 422: Wireless Communication Networks