WiMAX is a wireless technology that can provide broadband access over long distances. It uses wireless transmission in the 2-11 GHz range to connect users to a base station up to 50 km away. From the base station, users can access the internet and other public networks at speeds up to 70 Mbps shared among users. WiMAX allows both line-of-sight and non-line-of-sight connections using adaptive burst profiles. It has the potential to provide high-speed wireless internet access to areas not reached by cables and DSL.
The document discusses several IEEE 802 standards for local and metropolitan area networks. It describes the purpose of IEEE 802 standards to define physical network interfaces and the lowest three layers of the network architecture. It provides details on some famous IEEE 802 standards including 802.2 (LLC), 802.3 (Ethernet), 802.4 (Token Bus), 802.5 (Token Ring), 802.6 (DQDB), and 802.11 (Wireless LAN). It then focuses on explaining the Ethernet, Token Bus and Token Ring standards in more depth including their frame formats and other specifications.
This document discusses different types of virtual private networks (VPNs) and their requirements. It describes four main types of VPNs: virtual leased lines, virtual private routed networks, virtual private LAN segments, and virtual private dial networks. For each type, it outlines their motivations, implementations, requirements around tunneling protocols, addressing, and quality of service guarantees. Further standardization is needed on a generic VPN identifier, membership configuration and dissemination, and addressing security and scalability issues.
This document discusses medium access control (MAC) protocols, which regulate access to a shared wireless medium between nodes. It covers key requirements for MAC protocols including throughput efficiency, fairness, and low overhead. It also describes challenges like the hidden terminal problem, exposed terminal problem, and sources of overhead from collisions, overhearing, and idle listening. Finally, it categorizes common MAC protocols as fixed assignment, demand assignment, and random access and notes additional energy conservation requirements for wireless sensor networks.
The document discusses medium access control (MAC) protocols for wireless ad-hoc networks. It describes several MAC protocols including the Five Phase Reservation Protocol (FPRP) and Distributed Wireless Ordering Protocol (DWOP). FPRP uses a five phase process for distributed reservation of time slots. DWOP aims to provide fair channel access that approximates a first-in-first-out scheduling order by sharing packet arrival times between nodes. The document evaluates these protocols and discusses their advantages in providing quality of service guarantees and fair scheduling in wireless ad-hoc networks.
1) Medium Access Control (MAC) protocols regulate access to shared wireless channels and ensure performance requirements of applications are met. They assemble data into frames, append addressing and error detection, and disassemble received frames.
2) Common MAC protocols include Fixed Assignment (e.g. TDMA), Demand Assignment (e.g. polling), and Random Assignment (e.g. ALOHA, CSMA). Schedule-based MAC protocols avoid contention through resource scheduling while contention-based protocols (e.g. CSMA/CA) allocate resources on demand, risking collisions.
3) The document discusses various MAC protocols for wireless sensor networks and their objectives to minimize energy waste from idle listening, collisions,
The document discusses several mechanisms used in TCP for mobile computing. It describes:
1) TCP congestion control mechanisms like slow-start and fast retransmit/fast recovery which are designed to address packet loss. However, these can be inappropriate for wireless networks where packet loss is often due to errors rather than congestion.
2) Approaches like Indirect TCP, Snooping TCP, and Mobile TCP which modify TCP for mobile networks by splitting connections or having a supervisory host monitor the connection to enable local retransmissions and avoid unnecessary window reductions when the mobile host disconnects.
3) Other TCP optimizations for mobile like forced fast retransmit after handovers and transmission timeout freezing to avoid slow-start
The document summarizes an Ethernet switching product called the DMSwitch 3000. It supports up to 24 Fast Ethernet and 4 Gigabit Ethernet interfaces in a 1U chassis. Key features include stacking of up to 8 units, advanced QoS, security, management capabilities, VLAN support, routing protocols, and various fiber optic SFP modules. It provides carrier-class switching for metro Ethernet networks.
The document discusses several IEEE 802 standards for local and metropolitan area networks. It describes the purpose of IEEE 802 standards to define physical network interfaces and the lowest three layers of the network architecture. It provides details on some famous IEEE 802 standards including 802.2 (LLC), 802.3 (Ethernet), 802.4 (Token Bus), 802.5 (Token Ring), 802.6 (DQDB), and 802.11 (Wireless LAN). It then focuses on explaining the Ethernet, Token Bus and Token Ring standards in more depth including their frame formats and other specifications.
This document discusses different types of virtual private networks (VPNs) and their requirements. It describes four main types of VPNs: virtual leased lines, virtual private routed networks, virtual private LAN segments, and virtual private dial networks. For each type, it outlines their motivations, implementations, requirements around tunneling protocols, addressing, and quality of service guarantees. Further standardization is needed on a generic VPN identifier, membership configuration and dissemination, and addressing security and scalability issues.
This document discusses medium access control (MAC) protocols, which regulate access to a shared wireless medium between nodes. It covers key requirements for MAC protocols including throughput efficiency, fairness, and low overhead. It also describes challenges like the hidden terminal problem, exposed terminal problem, and sources of overhead from collisions, overhearing, and idle listening. Finally, it categorizes common MAC protocols as fixed assignment, demand assignment, and random access and notes additional energy conservation requirements for wireless sensor networks.
The document discusses medium access control (MAC) protocols for wireless ad-hoc networks. It describes several MAC protocols including the Five Phase Reservation Protocol (FPRP) and Distributed Wireless Ordering Protocol (DWOP). FPRP uses a five phase process for distributed reservation of time slots. DWOP aims to provide fair channel access that approximates a first-in-first-out scheduling order by sharing packet arrival times between nodes. The document evaluates these protocols and discusses their advantages in providing quality of service guarantees and fair scheduling in wireless ad-hoc networks.
1) Medium Access Control (MAC) protocols regulate access to shared wireless channels and ensure performance requirements of applications are met. They assemble data into frames, append addressing and error detection, and disassemble received frames.
2) Common MAC protocols include Fixed Assignment (e.g. TDMA), Demand Assignment (e.g. polling), and Random Assignment (e.g. ALOHA, CSMA). Schedule-based MAC protocols avoid contention through resource scheduling while contention-based protocols (e.g. CSMA/CA) allocate resources on demand, risking collisions.
3) The document discusses various MAC protocols for wireless sensor networks and their objectives to minimize energy waste from idle listening, collisions,
The document discusses several mechanisms used in TCP for mobile computing. It describes:
1) TCP congestion control mechanisms like slow-start and fast retransmit/fast recovery which are designed to address packet loss. However, these can be inappropriate for wireless networks where packet loss is often due to errors rather than congestion.
2) Approaches like Indirect TCP, Snooping TCP, and Mobile TCP which modify TCP for mobile networks by splitting connections or having a supervisory host monitor the connection to enable local retransmissions and avoid unnecessary window reductions when the mobile host disconnects.
3) Other TCP optimizations for mobile like forced fast retransmit after handovers and transmission timeout freezing to avoid slow-start
The document summarizes an Ethernet switching product called the DMSwitch 3000. It supports up to 24 Fast Ethernet and 4 Gigabit Ethernet interfaces in a 1U chassis. Key features include stacking of up to 8 units, advanced QoS, security, management capabilities, VLAN support, routing protocols, and various fiber optic SFP modules. It provides carrier-class switching for metro Ethernet networks.
The document discusses Plesiochronous Digital Hierarchy (PDH) and Synchronous Digital Hierarchy (SDH) technologies. PDH uses bit interleaving to transmit multiple digital signals over fiber optic or microwave networks at nearly synchronized rates. SDH was developed as international standard to overcome limitations of PDH like inefficient bandwidth usage. SDH uses synchronous transmission and defines a hierarchical structure of containers, tributaries and frames to efficiently transport digital signals and switch traffic.
The document discusses the components and characteristics of wireless local area networks (WLANs). It describes the basic components of a WLAN including access points, WLAN adapters, and software. It discusses characteristics such as typical ranges of access points, the number of users supported, and how multiple access points can be connected. It also covers topics such as roaming between access points, infrastructure versus ad-hoc network architectures, and standards like IEEE 802.11.
The document discusses various topics related to multicast routing including: 1) classification of multicast routing protocols based on path construction and maintenance, 2) optimized and overlay multicast routing approaches that bypass traditional deployment, and 3) challenges and approaches for multicast routing in mobile and inter-domain contexts.
GPRS is a packet-based mobile data service on GSM networks. It provides higher speed data transmission than previous GSM data services. The GPRS architecture introduces two new network nodes - SGSN and GGSN. SGSN handles mobility management and packet transmission between MS and GGSN, while GGSN connects the GPRS network to external packet networks like the Internet. GPRS enhances the GSM network by allowing dynamic allocation of bandwidth and intermittent data transmission, making it suitable for bursty, low-volume data applications.
This document discusses multicasting and multicast routing protocols. It defines unicast, multicast, and broadcast messages and describes applications of multicasting like accessing distributed databases and teleconferencing. It also explains different multicast routing protocols including MOSPF, DVMRP, CBT, and PIM, covering concepts like shortest path trees, flooding, and pruning. Finally, it describes MBONE which connects isolated multicast routers using tunneling.
Mac protocols sensor_20071105_slideshareChih-Yu Lin
This document summarizes several MAC protocols for wireless sensor networks. It begins by introducing the need for MAC protocols to control medium access in wireless networks and common sources of energy waste. It then categorizes MAC protocols as contention-based (like ALOHA and CSMA), schedule-based (like TDMA), or hybrid. Specific protocols discussed include S-MAC, B-MAC, TRAMA, and hybrid protocols like Z-MAC and Funneling-MAC. The document emphasizes energy efficiency as the primary concern for MAC protocols in wireless sensor networks.
Code division multiple access (CDMA) allows all terminals to send signals simultaneously over the same frequency by assigning each terminal a unique spreading code. The receiver can isolate a particular sender's signal by correlating the received signal with the known spreading code. CDMA offers advantages like higher capacity and integration of encryption due to the use of spreading codes, though receivers are more complex.
This document provides an overview of LTE air interface concepts including:
- Main LTE features such as frequency bands and mobility protocols.
- The LTE protocol stack including layers such as RRC, PDCP, RLC, MAC and physical.
- LTE channel types including logical, transport, and physical channels.
- Key physical channel functions like reference signals, synchronization signals, broadcast channels, and control channels.
- Uplink/downlink channel structures including time and frequency domain configurations.
The document summarizes key points from an 8th lecture on wireless sensor networks. It discusses various medium access control (MAC) protocols that control when nodes can access a shared wireless medium. These include contention-based protocols like MACA that use RTS/CTS handshaking and schedule-based protocols with fixed or dynamic scheduling. It also describes energy-efficient MAC protocols for low data rate sensor networks like S-MAC, T-MAC, and preamble sampling that increase sleep time to reduce energy use through synchronized sleep schedules or long preambles.
SMDS (Switched Multimegabit Data Service) is a connectionless wide area networking service designed for LAN interconnection over public telephone networks. It uses a series of SMDS switches to provide moderate bandwidth connections between 1-34 Mbps. Key interfaces for SMDS include SIP (SMDS Interface Protocol) between customer equipment and the network, and ISSI between SMDS switches. While gaining popularity for moderate bandwidth LAN interconnectivity, SMDS faces competition from newer technologies like Frame Relay and ATM.
Lecture 7 8 ad hoc wireless media access protocolsChandra Meena
1) The document discusses issues with media access control (MAC) protocols in ad hoc wireless networks, including problems like hidden terminals and exposed nodes.
2) It classifies MAC protocols as synchronous, asynchronous, receiver-initiated, or sender-initiated. The RTS-CTS handshake is presented as a solution to the hidden terminal problem.
3) However, the RTS-CTS approach has shortcomings like collisions when RTS and CTS messages are sent by different nodes or when multiple CTS messages are granted. Solutions to the exposed node problem are also discussed.
This document provides an overview of wireless local area networks (WLANs), including:
- The advantages and disadvantages of WLANs compared to wired networks.
- A comparison of infrared and radio transmission methods.
- A comparison of infrastructure and ad-hoc network architectures.
- An overview of the IEEE 802.11 standard including physical layer specifications and the distributed coordination function (DCF) medium access control protocol.
The document provides an overview of the IEEE 802.11 protocol, describing its architecture, layers, and key mechanisms. The standard defines a cellular architecture with basic service sets (BSS) controlled by access points. It covers the MAC and physical layers, defining fragmentation/reassembly and carrier sense multiple access with collision avoidance (CSMA/CA) for medium access. Request to send/clear to send frames are used for virtual carrier sensing to reduce collisions between hidden stations.
WIMAX (Worldwide Interoperability for Microwave Access) is a wireless communication protocol that provides longer range and higher bandwidth than WiFi. It uses a system of towers and receivers to provide internet access to homes and businesses over long distances without wires. WIMAX employs various techniques like ARQ, FEC and H-ARQ to make data transmission over the unreliable airlink more reliable. For ARQ, it uses methods like stop-and-wait, sliding window with go-back-N and selective repeat to handle lost packets. It also uses FEC codes for error correction and H-ARQ combines ARQ and FEC.
This document discusses the architecture of GPRS (General Packet Radio Service) networks. It describes the GPRS subscriber profile, which contains information about the services a subscriber is allowed to use, including packet data protocols and quality of service parameters. It then explains the GPRS quality of service profile in depth, covering precedence class, delay class, reliability class, and throughput classes. Finally, it provides an overview of GPRS logical functions and network elements, interfaces, and the transfer of packets between GPRS support nodes.
This document describes three TCP-aware link layer protocols: Snooping TCP, Wireless TCP, and Delayed DACK. Snooping TCP uses an agent at the base station to snoop and buffer TCP connections, ensuring packets are delivered to the mobile node in order and retransmitting lost packets. Wireless TCP modifies timestamps to compensate for increased round-trip time. Delayed DACK delays acknowledgments to allow time for lost packets to be recovered before triggering retransmissions.
The document provides an overview of LTE and its evolution from previous cellular standards. It discusses the targets of LTE including high data rates up to 100 Mbps, low latency, high spectral efficiency, and flexibility in spectrum and bandwidth. It also describes the EPS architecture with E-UTRAN, EPC, and the air interface structure of LTE including OFDMA in the downlink and SC-FDMA in the uplink. Key layers like the PHY, MAC, and RLC layers are also summarized.
The document discusses various channels used in GSM networks. It describes physical channels that transfer bits between network elements and logical channels distinguished by the nature of carried information. It provides details on different types of logical channels including traffic, broadcast, common control and dedicated control channels. It also explains concepts like bursts, frames, multiframe structures and how they are used to organize speech and data on traffic channels.
The Ultimate Data-Driven Marketing Survival GuideDaniel Robinson
Venturing into the thick forests of marketing and advertising can sometimes be daunting, the forest grows ever more complex, the skills needed to navigate your way more rigorous.
The lifeline that leads your way, which shines like the lighthouse beam on a stormy sea; DATA…
Data is critical to your survival and your ability to thrive in this harsh environment.
Your data strategy is the shelter and warmth that will provide protection and cover during your quest.
Data relating to content is your nourishment, the food and water that feeds your journey.
Your analytics data is your compass and your navigation mechanism, allowing you to know you are on track and enabling you to alter your course if you are being led astray.
You need tools and equipment for your journey and the technology you take with you can make all the difference – without a good knife where would we be…
And of course your magic key of data activation, it unlocks the value in your kit and lets you develop insight that will lead you to your destination.
So to help you weary travellers along your quest, to arm you with the best advantage and invigorate you with knowledge, ADMA are happy to share with you the DATA SURVIVAL GUIDE; everything you need to succeed. Produced in conjunction with the valiant speakers coming to you at ADMA Data Day in Sydney on the 27th April and Melbourne on the 29th April where more secrets will be revealed…
Listing of luxury properties sold and for sale in FranceImmocoach
Find out our non-exhaustive listing of luxury properties in the South of France.
More infos on www.immocoach.fr or send us an email on contact@immocoach.fr
The document discusses Plesiochronous Digital Hierarchy (PDH) and Synchronous Digital Hierarchy (SDH) technologies. PDH uses bit interleaving to transmit multiple digital signals over fiber optic or microwave networks at nearly synchronized rates. SDH was developed as international standard to overcome limitations of PDH like inefficient bandwidth usage. SDH uses synchronous transmission and defines a hierarchical structure of containers, tributaries and frames to efficiently transport digital signals and switch traffic.
The document discusses the components and characteristics of wireless local area networks (WLANs). It describes the basic components of a WLAN including access points, WLAN adapters, and software. It discusses characteristics such as typical ranges of access points, the number of users supported, and how multiple access points can be connected. It also covers topics such as roaming between access points, infrastructure versus ad-hoc network architectures, and standards like IEEE 802.11.
The document discusses various topics related to multicast routing including: 1) classification of multicast routing protocols based on path construction and maintenance, 2) optimized and overlay multicast routing approaches that bypass traditional deployment, and 3) challenges and approaches for multicast routing in mobile and inter-domain contexts.
GPRS is a packet-based mobile data service on GSM networks. It provides higher speed data transmission than previous GSM data services. The GPRS architecture introduces two new network nodes - SGSN and GGSN. SGSN handles mobility management and packet transmission between MS and GGSN, while GGSN connects the GPRS network to external packet networks like the Internet. GPRS enhances the GSM network by allowing dynamic allocation of bandwidth and intermittent data transmission, making it suitable for bursty, low-volume data applications.
This document discusses multicasting and multicast routing protocols. It defines unicast, multicast, and broadcast messages and describes applications of multicasting like accessing distributed databases and teleconferencing. It also explains different multicast routing protocols including MOSPF, DVMRP, CBT, and PIM, covering concepts like shortest path trees, flooding, and pruning. Finally, it describes MBONE which connects isolated multicast routers using tunneling.
Mac protocols sensor_20071105_slideshareChih-Yu Lin
This document summarizes several MAC protocols for wireless sensor networks. It begins by introducing the need for MAC protocols to control medium access in wireless networks and common sources of energy waste. It then categorizes MAC protocols as contention-based (like ALOHA and CSMA), schedule-based (like TDMA), or hybrid. Specific protocols discussed include S-MAC, B-MAC, TRAMA, and hybrid protocols like Z-MAC and Funneling-MAC. The document emphasizes energy efficiency as the primary concern for MAC protocols in wireless sensor networks.
Code division multiple access (CDMA) allows all terminals to send signals simultaneously over the same frequency by assigning each terminal a unique spreading code. The receiver can isolate a particular sender's signal by correlating the received signal with the known spreading code. CDMA offers advantages like higher capacity and integration of encryption due to the use of spreading codes, though receivers are more complex.
This document provides an overview of LTE air interface concepts including:
- Main LTE features such as frequency bands and mobility protocols.
- The LTE protocol stack including layers such as RRC, PDCP, RLC, MAC and physical.
- LTE channel types including logical, transport, and physical channels.
- Key physical channel functions like reference signals, synchronization signals, broadcast channels, and control channels.
- Uplink/downlink channel structures including time and frequency domain configurations.
The document summarizes key points from an 8th lecture on wireless sensor networks. It discusses various medium access control (MAC) protocols that control when nodes can access a shared wireless medium. These include contention-based protocols like MACA that use RTS/CTS handshaking and schedule-based protocols with fixed or dynamic scheduling. It also describes energy-efficient MAC protocols for low data rate sensor networks like S-MAC, T-MAC, and preamble sampling that increase sleep time to reduce energy use through synchronized sleep schedules or long preambles.
SMDS (Switched Multimegabit Data Service) is a connectionless wide area networking service designed for LAN interconnection over public telephone networks. It uses a series of SMDS switches to provide moderate bandwidth connections between 1-34 Mbps. Key interfaces for SMDS include SIP (SMDS Interface Protocol) between customer equipment and the network, and ISSI between SMDS switches. While gaining popularity for moderate bandwidth LAN interconnectivity, SMDS faces competition from newer technologies like Frame Relay and ATM.
Lecture 7 8 ad hoc wireless media access protocolsChandra Meena
1) The document discusses issues with media access control (MAC) protocols in ad hoc wireless networks, including problems like hidden terminals and exposed nodes.
2) It classifies MAC protocols as synchronous, asynchronous, receiver-initiated, or sender-initiated. The RTS-CTS handshake is presented as a solution to the hidden terminal problem.
3) However, the RTS-CTS approach has shortcomings like collisions when RTS and CTS messages are sent by different nodes or when multiple CTS messages are granted. Solutions to the exposed node problem are also discussed.
This document provides an overview of wireless local area networks (WLANs), including:
- The advantages and disadvantages of WLANs compared to wired networks.
- A comparison of infrared and radio transmission methods.
- A comparison of infrastructure and ad-hoc network architectures.
- An overview of the IEEE 802.11 standard including physical layer specifications and the distributed coordination function (DCF) medium access control protocol.
The document provides an overview of the IEEE 802.11 protocol, describing its architecture, layers, and key mechanisms. The standard defines a cellular architecture with basic service sets (BSS) controlled by access points. It covers the MAC and physical layers, defining fragmentation/reassembly and carrier sense multiple access with collision avoidance (CSMA/CA) for medium access. Request to send/clear to send frames are used for virtual carrier sensing to reduce collisions between hidden stations.
WIMAX (Worldwide Interoperability for Microwave Access) is a wireless communication protocol that provides longer range and higher bandwidth than WiFi. It uses a system of towers and receivers to provide internet access to homes and businesses over long distances without wires. WIMAX employs various techniques like ARQ, FEC and H-ARQ to make data transmission over the unreliable airlink more reliable. For ARQ, it uses methods like stop-and-wait, sliding window with go-back-N and selective repeat to handle lost packets. It also uses FEC codes for error correction and H-ARQ combines ARQ and FEC.
This document discusses the architecture of GPRS (General Packet Radio Service) networks. It describes the GPRS subscriber profile, which contains information about the services a subscriber is allowed to use, including packet data protocols and quality of service parameters. It then explains the GPRS quality of service profile in depth, covering precedence class, delay class, reliability class, and throughput classes. Finally, it provides an overview of GPRS logical functions and network elements, interfaces, and the transfer of packets between GPRS support nodes.
This document describes three TCP-aware link layer protocols: Snooping TCP, Wireless TCP, and Delayed DACK. Snooping TCP uses an agent at the base station to snoop and buffer TCP connections, ensuring packets are delivered to the mobile node in order and retransmitting lost packets. Wireless TCP modifies timestamps to compensate for increased round-trip time. Delayed DACK delays acknowledgments to allow time for lost packets to be recovered before triggering retransmissions.
The document provides an overview of LTE and its evolution from previous cellular standards. It discusses the targets of LTE including high data rates up to 100 Mbps, low latency, high spectral efficiency, and flexibility in spectrum and bandwidth. It also describes the EPS architecture with E-UTRAN, EPC, and the air interface structure of LTE including OFDMA in the downlink and SC-FDMA in the uplink. Key layers like the PHY, MAC, and RLC layers are also summarized.
The document discusses various channels used in GSM networks. It describes physical channels that transfer bits between network elements and logical channels distinguished by the nature of carried information. It provides details on different types of logical channels including traffic, broadcast, common control and dedicated control channels. It also explains concepts like bursts, frames, multiframe structures and how they are used to organize speech and data on traffic channels.
The Ultimate Data-Driven Marketing Survival GuideDaniel Robinson
Venturing into the thick forests of marketing and advertising can sometimes be daunting, the forest grows ever more complex, the skills needed to navigate your way more rigorous.
The lifeline that leads your way, which shines like the lighthouse beam on a stormy sea; DATA…
Data is critical to your survival and your ability to thrive in this harsh environment.
Your data strategy is the shelter and warmth that will provide protection and cover during your quest.
Data relating to content is your nourishment, the food and water that feeds your journey.
Your analytics data is your compass and your navigation mechanism, allowing you to know you are on track and enabling you to alter your course if you are being led astray.
You need tools and equipment for your journey and the technology you take with you can make all the difference – without a good knife where would we be…
And of course your magic key of data activation, it unlocks the value in your kit and lets you develop insight that will lead you to your destination.
So to help you weary travellers along your quest, to arm you with the best advantage and invigorate you with knowledge, ADMA are happy to share with you the DATA SURVIVAL GUIDE; everything you need to succeed. Produced in conjunction with the valiant speakers coming to you at ADMA Data Day in Sydney on the 27th April and Melbourne on the 29th April where more secrets will be revealed…
Listing of luxury properties sold and for sale in FranceImmocoach
Find out our non-exhaustive listing of luxury properties in the South of France.
More infos on www.immocoach.fr or send us an email on contact@immocoach.fr
The document discusses the EU ETS carbon market and emissions trading scheme. It is related to a Master's 1 program in energy and the contact person is provided as F.BENHMAD at the University of Montpellier with an email address.
Many persons in the present point in time are in front of the trouble of financial debts and are not able to pay, Payday loans. If you want to dispose of this trouble fast and want gladness in your living yet again then you must have to get up a speedy payday loan debt consolidation service. We at paydayloanconsolidation.biz make obtainable you payday loan debt consolidation services that may gain this amount and interest rates downsize.
Wemakedesign is a branding and design consultancy established in 2004 focusing on identity and brand creation for small and medium businesses. They have since expanded to work with both large corporations and emerging enterprises. The document provides an overview of Wemakedesign's services and approach, as well as profiles of the creative partners and examples of work. Their process involves discovery, definition, creation, and implementation phases to develop brand strategies and visual identities that meet client objectives.
The document discusses Activity Based Costing (ABC), an approach for assigning overhead costs to products and services. It notes that traditional costing methods can misallocate overhead, affecting management decisions. ABC addresses this by tracing overhead costs to the activities that cause those costs, and then assigning the costs of each activity to products based on their use of that activity. This provides a more accurate picture of product costs. The document outlines the basic concepts and steps of implementing ABC, including identifying activities, assigning resource costs to activities, defining activity cost drivers, and calculating activity costs to allocate to cost objects like products.
Mars Travelport offers various tour packages in India including adventure tours, pilgrimage tours, wildlife tours, and medical tours. Some highlighted adventure tours include trekking in Ladakh, river rafting in Rishikesh, and camping in Chopta and Har Ki Dun. Mars Travelport also provides luxury car rentals and is a one-stop shop for all travel needs, offering transportation, tours, and corporate event planning services.
El documento presenta las reglas para multiplicar expresiones algebraicas. Explica que al multiplicar términos se multiplican primero los signos, luego los coeficientes, y por último se suman los exponentes de las mismas letras. Proporciona un ejemplo de la multiplicación de un monomio por un monomio y de un binomio por un binomio. Finalmente, incluye un enlace a un video que ofrece más explicación sobre el tema.
Mars Travelport provides corporate travel services including employee transportation, luxury cars for rent, and planning meetings, incentives, conferences, and events. It aims to provide top quality and comfortable transportation solutions to businesses. Mars Travelport has a fleet of premium cars and coaches driven by uniformed chauffeurs. It works with many large corporations in sectors like banking, FMCG, hotels, and IT to transport employees. Mars Travelport believes providing ground transportation solutions can help clients enhance performance and be more productive while focusing on their core business. It also offers tours, travel, air charters, and wedding planning services.
This document contains a list of words and phrases that the author finds annoying or dislikes. Some examples included are "absolutely," "acrossed," "action" used as a verb, "actually," "alot," "amazing," "anyways," "as always," "athalete," "awesome" used to mean good, "big of a deal," "blog," "bottom-line," "bought brought," "bucket" used to mean category, "cervix," "chillax," "chortle," "clean" used as a noun, "cloister," "comfortable," "compartmentalize," "complected," "comprehensive," "consequently," and
This document summarizes a 1-year Diploma in Hospitality Management program offered by Aptech Aviation & Hospitality Academy in collaboration with Mahatma Gandhi University. The program trains students for careers in the hospitality sector, covering areas like food and beverage, front office, housekeeping, and more. It notes that the hospitality industry in India is worth $17 billion and needs 20,000 trained professionals per year, far more than the current supply. The diploma program includes modules over two semesters, a live project, optional internship, and placement support upon completion.
The document discusses wireless local area networks (WLANs) and personal area networks (PANs). It describes the characteristics and fundamentals of WLANs, including their advantages like flexibility and lower costs, and disadvantages such as lower bandwidth and security issues. It provides details on common wireless standards like IEEE 802.11, Bluetooth, and HomeRF. It also compares infrastructure-based and ad-hoc network topologies and summarizes key aspects of the IEEE 802.11 standard including services, physical layers, and frame formats.
This presentation briefly describes the Wi-Fi 6 Technology or the latest wi-fi: IEEE802.11ax which I have used at IIT Madras to present and explain my course work(reading assignment). here I have covered all the problems, solutions, and benefits of wi-fi 6, how Wi-Fi evolved, standards, security, advantages, and innovations.
This document provides an overview of Synchronous Digital Hierarchy (SDH) including its introduction, components, frame structure, and applications. SDH was developed to provide a standardized digital transmission network with vendor independence. It uses optical fiber to enable end-to-end monitoring and self-healing ring architectures for survivability. The SDH frame structure consists of sections for transport overhead (TOH), path overhead (POH), and payloads. SDH supports multiplexing of various signals like E1, DS1, and STM streams. It allows dynamic bandwidth allocation and is a platform for future services.
WiMAX is a wireless technology that provides broadband internet access over long distances. It uses radio waves to transmit data and can provide connectivity up to 30 miles from a base station. WiMAX uses the IEEE 802.16 standard and consists of components like the base station, receiver, and antennas. It establishes connections like cellular networks but provides faster speeds than WiFi for connecting larger areas.
The document provides information about wireless networks and standards including IEEE 802.11 (Wi-Fi), Bluetooth, and WiMAX. It discusses the goals and architecture of wireless LANs and PANs, as well as standards like IEEE 802.11, Bluetooth, and their protocols. Key topics covered include the IEEE 802.11 standard including physical layer specifications and MAC architecture, Bluetooth architecture and piconet/scatternet topologies, and protocols in the Bluetooth and IEEE 802.11 stacks.
This document provides an overview of wireless LAN and Bluetooth technologies. It describes IEEE 802.11 standards for wireless LAN including the basic service set, extended service set, infrastructure and ad-hoc modes. It covers the physical layers, MAC protocols and services of 802.11. It also summarizes ATM and its extension to wireless networks, issues in the transition, proposed W-ATM architectures, advantages and disadvantages. Finally it defines Bluetooth technology, the protocol stack and unlicensed frequency band used.
This document provides an overview of a lecture on wireless communication systems. The lecture covers Wireless Local Area Networks (WLAN) standards such as 802.11b, 802.11a, and 802.11g. It also discusses emerging wireless technologies including Bluetooth, Ultra-Wideband (UWB), WiMax, and the fusion of telephony and IP networks. The lecture focuses in more detail on WiMax and Bluetooth standards, characteristics, architectures, and applications.
This document provides an overview of a lecture on wireless communication systems. The lecture covers Wireless Local Area Networks (WLAN) standards such as 802.11b, 802.11a, and 802.11g. It also discusses emerging wireless technologies including Bluetooth, Ultra-Wideband (UWB), WiMax, and the fusion of telephony and IP networks. The lecture focuses in more detail on WiMax and Bluetooth standards, characteristics, architectures, and applications.
WiMAX is a wireless technology that can provide broadband internet access over long distances. It uses multiplexing techniques like OFDM and OFDMA to allow efficient use of spectrum. The document discusses WiMAX network architecture including components like the base station, CPE/MS, and ASN-GW. It also covers topics like QoS classes, modulation schemes, antennas, and applications of WiMAX such as providing VoIP services.
WiMAX 2.0 is an update to the WiMAX standard that aims to provide higher data rates, lower latencies, and improved coverage compared to the original WiMAX 1.0 standard. It defines new physical and MAC layer specifications using OFDMA, supports carrier aggregation across multiple frequency bands, introduces advanced antenna techniques, and defines quality of service classes to efficiently allocate bandwidth. The document reviews the reasons for the WiMAX 2.0 update and key features such as increased data rates up to 1 Gbps, reduced framing overhead, support for heterogeneous networks, and enhanced interworking capabilities with other wireless technologies.
This document provides an overview of WiMAX and the IEEE 802.16 standards for broadband wireless access. It describes key aspects of the 802.16 MAC including its reference model, addressing, connection-oriented design, quality of service support, and uplink/downlink frame structures. It also summarizes the MAC convergence and common part sublayers, addressing, management connections, and bandwidth request mechanisms.
WiMAX is a wireless technology that provides broadband connections over long distances. It uses towers to transmit high-speed Internet access to homes and businesses without wires. WiMAX operates using either line-of-sight or non-line-of-sight connections and can provide data rates between 30-40 megabits per second for mobile use and up to 1 gigabit per second for fixed locations. The WiMAX network is made up of towers, base stations, and an access service network that connects subscribers. It supports features like adaptive modulation, link-layer retransmissions, quality of service guarantees, and strong security.
The document provides an overview of WiFi networks and various IEEE 802.11 standards. It discusses basic WiFi concepts and deployment issues. It then summarizes several key WiFi versions including 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and 802.11ad and how each standard improved data rates and functionality compared to previous versions through techniques like channel bonding and MIMO.
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WiGig and HaLow operate at new Wi-Fi frequency bands. WiGig operates at 60GHz for wireless docking, HD video connections, and data rates up to 6.75Gbps. HaLow operates at sub-1GHz frequencies for low-power wide-area IoT applications, with data rates from 150kbps to 234Mbps and a range of over 1km. Both standards add new features to existing Wi-Fi standards to enable new use cases while maintaining compatibility.
The document discusses the history and status of the IEEE 802.11n standard for wireless local area networks. It began development in 2004 with the goal of increasing data throughput up to 540 Mbps. Two competing proposals were eventually merged. Key technologies included in the standard are MIMO and OFDM to improve throughput and range. The standard was finalized in 2006 and incorporated new technologies to support throughput up to 600 Mbps.
AWMN Ultra-band Advanced wireless and .pptxshashijntuhceh
Ultra-wideband (UWB) technology uses very short radio pulses to transmit data over a large bandwidth, allowing for high data rates with low power consumption. There are two competing UWB standards - DS-UWB uses a single pulse across multiple gigahertz, while MB-OFDM divides the spectrum into sub-bands and hops between them. Both provide security through AES-128 encryption at the MAC layer. Potential applications include high-speed cable replacement technologies, but incompatible standards and signal degradation over distance present challenges to widespread adoption.
Secure and Service-Oriented Network Control Framework for WiMAX Networks
IEEE 802.16 supports both TDD ( time-division duplex) and FDD (frequency-division duplex)
Multihop communication is needed for deployment of wimax network. Because of multihop
Security is issues associated with wimax network
Issue is how to support different services and applications in WiMAX networks
The document discusses key aspects of the IEEE 802.16 WiMAX standard. It describes WiMAX as providing broadband wireless access over long distances with high speeds. It outlines the MAC layer standards, including sublayers for convergence and management. It details the MAC frame structure, addressing, and scheduling priorities for different traffic types. Finally, it discusses advantages like mobility support, disadvantages like power consumption, and future applications of WiMAX technology.
This document provides an overview of basic switching concepts and switch configuration. It discusses Ethernet networking fundamentals such as CSMA/CD access method, collisions, broadcast traffic, latency, and errors. It also covers segmentation methods for networks including bridges, routers, and switches which divide collision domains to improve performance. Switches are described as multiport bridges that microsegment networks by connecting each device to its own dedicated switch port.
2. Contents
• Introduction
• What is WiMAX?
• IEEE 802.16 Extensions
• Architecture
• Functionality
• WiMAX Protocol
• Scenario
• Features
• Security Issues
• Benefits
• WiFi vs WiMAX
• WiMAX Applications
• Future of WiMAX
• Conclusion
• References
3. Introduction
• Broadband accessBroadband access - In your home, you have either a DSL or- In your home, you have either a DSL or
cable modem At the office, your company may be using a T1cable modem At the office, your company may be using a T1
or T3 line.or T3 line.
• WiFi accessWiFi access - In your home, you may have set up a WiFi
router that lets you surf the Web while you lounge with your
laptop on the road, you can find WiFi hot spots in restaurants,
hotels, coffee shops and libraries.
• Dial-up access - If you are still using dial-up, chances are that
either broadband access is not available, or you think that
broadband access is too expensive
4. Contd..
• The main problems with broadband access are that it is
pretty expensive and it doesn't reach all areas.
• The main problem with WiFi access is that hot spots are
very small, so coverage is sparse.
• There is a need for a system which provides high speed of
Broadband and is wireless instead of wired.
• WiMAX(Worldwide Interoperability Microwave Access)
provides these features .Its also known as IEEE 802.16
5. What is WiMAX?
• WiMAX (Worldwide Interoperability for microwave access)
•
A technology based on an evolving standard for point-to-
multi point wireless networking
•
The commercialization of IEEE 802.16 standard
•
Solution for Wireless Metropolitan Area Network
•
BWA (Broadband Wireless Access) Solution
•
Comply with European BWA standard
• European Telecommunications Standards Institutes's
High-performance radio metropolitan area network
(HiperMAN)
8. Operation of WiMAX
• WiMAX consists of two parts
• A WiMAX tower, similar in concept to a cell-phone tower -
A single WiMAX tower can provide coverage to a very
large area -- as big as 3,000 square miles
• A WiMAX Receiver The receiver and antenna could be a
small box or PCMCIA card, or they could be built into a
laptop the way WiFi access is today
9. Service Types
• Non-Line-Of-Sight
•
A Service where a small antenna on your computer
connects to the tower. In this mode, WiMAX uses a lower
frequency range -- 2 GHz to 11 GHz (similar to WiFi)
• Line-Of-Sight
•
A Service where a fixed dish antenna points straight at the
WiMAX tower from a rooftop or pole. Line-of-sight
transmissions use higher frequencies, with ranges reaching
a possible 66 GHz
10.
11. IEEE 802.16
• IEEE 802.16 was completed on Oct, 2004
• Range - 30-mile (50-km) radius from base station
• Speed - 70 megabits per second
• Line-of-sight not needed between user and base station
• Frequency bands - 2 to 11 GHz and 10 to 66 GHz (licensed and
unlicensed bands)
• Defines both the MAC and PHY layers and allows multiple PHY-
layer specifications
12.
13. IEEE Extensions
• 802.16a
– use the licensed and license-exempt frequencies from 2 to 11Ghz
– Support Mesh-Network
• 802.16b
– Increase spectrum to 5 and 6GHz
– Provide QoS (for real-time voice and video service)
• 802.16c
– Represents a 10 to 66GHz system profile
• 802.16d
– Improvement and fixes for 802.16a
• 802.16e
– Addresses on Mobile
– Enable high-speed signal handoffs necessary for communications with
users moving at vehicular speeds
14.
15. Architecture
●
P2MP(Point to Multi point)
– Wireless MAN
– BS connected to Public Networks
– BS serves Subscriber Stations(SS)
– Provides SS with first mile access to Public Networks
●
Mesh Architecture
– Optional architecture for WiMAX
21. PHY Layer
• In the design of the PHY specification for 10–66 GHz, line-of-sight
propagation was deemed a practical necessity.
• Because of the point-to-multipoint architecture, the BS basically transmits
a TDM signal, with individual subscriber stations allocated time slots
serially.
• The PHY specification defined for 10–66 GHz uses burst single-carrier
modulation with adaptive burst profiling in which transmission
parameters, including the modulation and coding schemes, may be
adjusted individually to each subscriber station (SS) on a frame-by-frame
basis. Both TDD and burst FDD variants are defined.
• Channel bandwidths of 20 or 25 MHz (typical U.S. allocation) or 28
MHz (typical European allocation) are specified, along with Nyquist
square-root raised-cosine pulse shaping with a roll off factor of 0.25.
22. Contd..
●
Adaptive Burst Profiles
– On DL, multiple SS's can associate the same DL burst
– On UL, SS transmits in an given time slot with a
specific burst
●
Allows use of directional antennas
– Improves range
●
Allows use of two different duplexing schemes:
– Frequency Division Duplexing (FDD)
– Time Division Duplexing (TDD)
●
Support for both full and half duplex stations
24. FDD (Frequency Division
Duplexing)
●
In case of FDD both uplink and downlink channels are on
separate frequencies
●
The capability of downlink to be transmitted in bursts
simultaneously supports two different modulation types
– Full Duplex SS's( which can transmit and receive
simultaneously)
– Half Duplex SS's( which cannot)
26. TDD (Time Division Duplexing)
●
In case of TDD both uplink and downlink transmissions
share the same frequency but are separated on time
●
A TDD frame has a fixed duration and also consists of one
uplink and one downlink frame
●
TDD framing is Adaptive
29. Medium Access Control(MAC)
●
WirelessMAN: Point-to-Multipoint and optional mesh
topology
●
Connection-Oriented
– Connection ID(CID),Service Flows(FS)
●
MAC layer is further subdivided into three layers
– Convergence sub-layer (CS)
– Common part sub-layer (CPS)
– Privacy sub-layer
30. MAC Addressing
●
SS has 48-bit 802.3 MAC address
●
BS has 48-bit base station ID
– Not a MAC address
●
Connection ID (CID)
– 16 bit
– Used in MAC PDU
– Connection Oriented Service
31. Frame Structure and PDU
• Each MAC packet consists of the three components,
– A MAC header, which contains frame control
information.
– A variable length frame body, which contains
information specific to the frame type.
– A frame check sequence (FCS), which contains an
IEEE 32-bit cyclic redundancy code (CRC).
32. MAC PDU
CRC
(optional)MAC PDU payload (optional)
Generic MAC
Header
(6 bytes)
LEN
msb
(3)
H
T
CID msb (8)LEN lsb (8)
Generic MAC Header Format
(Header Type (HT) = 0)
BW Req. Header Format
(Header Type (HT) =1)
msb lsb
E
C
Type (6 bits)
rs
v
C
I
EKS
(2)
rs
v
HCS (8)CID lsb (8)
BW Req.
msb (8)
H
T
CID msb (8)BWS Req. lsb (8)
E
C
Type (6 bits)
HCS (8)CID lsb (8)
33. MAC CS Sub Layer
●
Interoperability requires convergence sub-layer to be service
specific
●
Separate CS layers for ATM & packet protocols
●
CS Layer:
– Receives data from higher layers
– Classifies data as ATM cell or packet
– Forwards frames to CPS layer
34. Contd..
●
Packet Convergence Sub-Layer
– Initial support for Ethernet, VLAN, IPv4, and IPv6
– Payload header suppression
– Full QoS support
●
ATM Convergence Sub-Layer
– Support for VP/VC switched connections
– Support for end-to-end signaling of dynamically
created connections
– ATM header suppression
– Full QOS support
35. MAC CPS Layer
●
Performs typical MAC functions such as addressing
– Each SS assigned 48-bit MAC address
– Connection Identifiers used as primary address after
initialization
●
MAC policy determined by direction of transmission
– Uplink is DAMA-TDM
– Downlink is TDM
●
Data encapsulated in a common format facilitating
interoperability
– Fragment or pack frames as needed
– Changes transparent to receiver
36. MAC PDU Types
●
Data MAC PDUs
– HT = 0
– Payloads are MAC SDUs/segments, i.e., data from
upper layer (CS PDUs)
– Transmitted on data connections
●
Management MAC PDUs
– HT =0
– Payloads are MAC management messages or IP packets
encapsulated in MAC CS PDUs
– Transmitted on management connections
●
BW Req. MAC PDUs
– HT =1; and no payload, i.e., just a Header
37. MAC PDU Transmission
●
MAC PDU’s are transmitted on PHY bursts
●
The PHY burst can contain multiple FEC blocks
●
Concatenation
– Multiple MAC PDU's can be concatenated into a single
transmission in either uplink or downlink direction
●
Fragmentation
– Each MAC SDU can be divided into one or more MAC
PDU's
●
Packing
– Packs multiple MAC SDU's into a single MAC PDU
38. MAC Privacy Sub Layer
●
Provides secure communication
– Data encrypted with cipher clock chaining mode of DES
●
Prevents theft of service
– SSs authenticated by BS using key management protocol
39. Transmission Convergence
Sublayer
• This layer performs the transformation of variable length
MAC protocol data units (PDUs) into the fixed length FEC
blocks (plus possibly a shortened block at the end) of each
burst.
• The TC layer has a PDU sized to fit in the FEC block
currently being filled. It starts with a pointer indicating
where the next MAC PDU header starts within the FEC
block. The TC PDU format allows resynchronization to the
next MAC PDU in the event that the previous FEC block
had irrecoverable errors.
40. WiMAX Scenario
•
Consider a scenario where a wimax-enabled computer is 10
miles away from the wimax base station.
•
A special encryption code is given to computer to gain
access to base station.
•
The base station would beam data from the Internet required
for computer (at speeds potentially higher than today's
cable modems)
41. Contd..
•The user would pay the provider monthly fee for using
the service. The cost for this service could be much
lower than current high-speed Internet-subscription fees
because the provider never had to run cables.
•The WiMAX protocol is designed to accommodate
several different methods of data transmission, one of
which is Voice Over Internet Protocol (VoIP).
• If WiMAX-compatible computers become very
common, the use of VoIP could increase dramatically.
Almost anyone with a laptop could make VoIP calls.
44. Scalability
•The 802.16 standard supports flexible radio frequency
(RF) channel bandwidths.
•The standard supports hundreds or even thousands of
users within one RF channel.
•As the number of subscribers grow the spectrum can
be reallocated with process of sectoring.
45. Quality Of Service
•Primary purpose of QoS feature is to define
transmission ordering and scheduling on the air
interface.
•These features often need to work in conjunction with
mechanisms beyond the air interface in order to
provide end to end QoS or to police the behaviour or
SS.
•Standard defines several QoS related concepts.
- Service flow Qos scheduling.
- Dynamic service Establishment.
-Two Phase Activation Model.
46. Theory Of Operation
•All protocol mechanisms support Qos for both uplink
and downlink traffic through the SS and BS.
•Requirements for QoS :
- A configuration and registration function to pre
configure SS based QoS service flows and traffic
parameters.
- A signalling function for dynamically establishing Qos
enabled service flows and traffic parameters.
- Utilization of MAC scheduling and QoS traffic
parameters for uplink service flows.
- Utilization of QoS traffic parameters for downlink
service flows.
47. Service flows
•A service flow is a MAC transport service that provides
unidirectional transport of packets either to uplink
packets transmitted by the SS or to downlink packets
transmitted by the BS.
•A service flow is characterized by a set of QoS
parameters such as latency,jitter and throughput
assurances.
•In order to standardize operations between SS and BS
these attributes include details of how the SS requests
uplink bandwidth allocations and the expected behaviour
of the BS uplink scheduler.
48.
49. Range
•Optimized for up to 50 Km.
•Designed to handle many users spread out over
kilometres.
•Designed to tolerate greater multi-path delay spread
(signal reflections) up to 10.0μ seconds.
•PHY and MAC designed with multi-mile range in mind.
51. Security Issues
•Security provides subscribers with privacy across the
fixes broadband wireless network.
•Security is implemented by encrypting connections
between SS and BS.
•Protection against unauthorized access to the data
transport services is done by enforcing encryption of the
associated service flows across the network.
52. Security Architecture
•Two component protocols:
- An encapsulation protocol for encrypting packet
data across fixed network.
- A key management protocol (PKM) providing the
secure distribution of keying data from BS to SS.
53. Packet Data Encryption
•Encryption services are defined as set of capabilities
within the MAC security sub layer.
•MAC Header information specific to encryption is
allocated in the generic MAC header format.
•Encryption is always applied to the MACPDU payload,
generic MAC is no encrypted.
•All MAC management messages shall be sent in clear
to facilitate registration,ranging and normal operation of
the MAC.
54. Key Management Protocol
•An SS uses the PKM protocol to obtain authorization
and traffic keying material from the BS.
•PKM protocol is also used for periodic reauthorization
and key refresh.
•PKM uses X.509 certificates and the RSA pubic -key
encryption algorithm to perform key exchanges
between SS and BS.
55. Contd..
•PKM protocol adheres to a client/server model.
•SS acts like PKM client and requests for keying material
and BS acts like PKM server and responds to the
requests ensuring that individual SS clients receive only
keying material for which they are authorized.
•PKM protocol uses MAC management messaging PKM-
RSP messages.
•PKM protocol uses public-key cryptography to establish
a shared secret between the SS and the BS.
56. Security Association
•A security Association is the set of security information a
BS and one or more of its clients SS s share in order to
support secure communication across the IEEE std 802.16
network.
•Three types of SA are defined:
Primary: SS establishes a primary security
association
during the SS initialization process.
Static: Static SA are provisioned within the BS.
Dynamic: Dynamic SA are established and
eliminated
on fly in response to the initiation and
termination of specific service flows.
•Static and Dynamic SA can be shared by multiple SS.
a
57.
58. Contd..
•
Figure conceptually depicts end-to-end Authentication,
Authorization, and Accounting (AAA) on 802.16 networks
supporting portability and fully mobile operations.
•
Encryption (security association) is established using the
PKM-EAP protocol.
•
Extensible Authentication Protocol (EAP) is carried over
RADIUS or DIAMETER to the AAA back end.
59. • Intel recommends using an end-to-end tunnelling
protocol such as Protected EAP (PEAP) or Tunnelled
TLS (TTLS) to afford mutual authentication.
• It also recommends 128-bit or better Transport Layer
Security (TLS) encryption to further enhance end-to-end
security (especially in situations where cryptographically
weaker EAP methods may be deployed).
Contd..
60. Benefits of WiMAX
●
Speed
– Faster than broadband service
●
Wireless
– Not having to lay cables reduces cost
– Easier to extend to suburban and rural areas
●
Broad coverage
– Much wider coverage than WiFi hotspots
61. Benefits for Network Service
Providers
•Allow service providers to deliver high throughput
broadband based services like VoIP, high-speed Internet
and Video
•Facilitate equipment compatibility
•Reduce the capital expenditures required for network
expansion
•Provide improved performance and extended range
•Allow service providers to achieve rapid ROI and
maximize revenues
62. Benefits for consumers
●
Range of technology and service level choices from both
fixed and wireless broadband operators
●
DSL-like services at DSL prices but with portability
●
Rapidly declining fixed broadband prices
●
No more DSL “installation” fees from incumbent
63. WiFi Vs WiMAX
• Scalability
• Relative Performance
• Quality of Service
• Range
• Coverage
• Security
64. Scalability
•
Channel bandwidths can be
chosen by operator (e.g. for
sectorization)
•
1.5 MHz to 20 MHz width
channels. MAC designed for
scalability. independent of
channel bandwidth
•
MAC designed to support
thousands of users.
•
Wide (20MHz) frequency
channels
•
MAC designed to support 10’s
of users
802.16a802.11
65. Relative Performance
5.0 bps/Hz100 Mbps1.5 – 20 MHz802.16a
2.7 bps/Hz54 Mbps20 MHz802.11
Maximum
bps/Hz
Maximum
Data Rate
Channel
Bandwidth
66. Quality Of Service (QoS)
•
Grant-request MAC
•
Designed to support Voice and
Video from ground up
•
Supports differentiated service
levels: e.g. T1 for business
customers; best effort for
residential.
•
Centrally-enforced QoS
•
Contention-based MAC
(CSMA/CA) => no guaranteed QoS
•
Standard cannot currently
guarantee latency for Voice, Video
•
Standard does not allow for
differentiated levels of service on a
per-user basis
•
802.11e (proposed) QoS is
prioritization only
802.16a802.11
67. Range
•
Optimized for up to 50 Km
•
Designed to handle many users
spread out over kilometers
•
Designed to tolerate greater
multi-path delay spread (signal
reflections) up to 10.0μ seconds
•
PHY and MAC designed with multi-
mile range in mind
•
Optimized for ~100 meters
•
No “near-far” compensation
•
Designed to handle indoor multi-
path delay spread of 0.8μ seconds
•
Optimization centers around PHY
and MAC layer for 100m range
802.16a802.11
68. Coverage
•
Optimized for outdoor NLOS
performance
•
Standard supports mesh network
topology
•
Standard supports advanced
antenna techniques
•
Optimized for indoor
performance
•
No mesh topology support within
ratified standards
802.16a802.11
69. Security
•
Existing standard is PKM - EAP•
Existing standard is WPA +
WEP
•
802.11i in process of addressing
security
802.16a802.11
70. Applications
●
Fixed last-mile broadband access as a replacement or
substitute for wired DSL, cable, or T1 connections
●
Inexpensive backhaul for cell sites and WiFi hotspots
●
High speed enterprise connectivity for businesses
●
Voice Over Internet Protocol (VOIP)
71.
72. Future of WiMAX
• WiMAX will be deployed in three phases
• In the first phase WiMAX technology (based on IEEE
802.16-2004) provides fixed wireless connections
• In the second phase WiMAX will be available as a cheap
and self-installing Subscriber Terminal (ST), linked to
PC and to antenna
• The third phase enables portability, thus WiMAX (based
on IEEE 802.16e) will be integrated into commercial
laptops.
75. WiMAX Forum
●
Worldwide Interoperability for Microwave Access
●
WiMAX was Founded in April 01’
●
No Profit organization comprised of wireless access system
manufacturers, component suppliers, software developers and carriers
●
A wireless industry consortium that supports and promotes WiMAX’s
commercial usage
●
Members include Intel, AT&T, Siemens Mobile, British
Telecommunications, etc..
●
Comply with the WiMAX standard and focus on the interoperability
76. Conclusion
●
WiMAX is poised to be the next Big Thing
●
WiMAX will connect you to the internet at faster speeds and
from much longer ranges
●
WiMAX can handle last-mile access in remote areas
●
Mobility can be achieved with design into computer chips
78. Questions
●
What are different kinds of service WIMAX offers and what
is difference between them?
●
How is interoperability achieved in WIMAX?
●
How is QOS implemented in WIMAX?
●
What is difference between P2MP and Mesh architectures?
●
List out three differences between WIMAX and WIFI?