Download Mobile Computing

What is Mobile Computing?
 Wireless Communication Systems
 Mobile Communication Systems Architecture
 Key Technologies of Mobile Computing
 Applications

Heterogeneous Wireless Communication World
DAB: Digital Audio Broadcast
VHE: Virtual Home Environment
DVB-T: Digital Video Broadcast Terrestrial
UMTS: Universal Mobile Telecommunication System
WIRELESS NETWORKS

Wireless communication networks
IEEE 802.11
 IEEE 802.15
 IEEE 802.16
 IEEE 802.20


Mobile communication networks
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GSM
GPRS
WCDMA
HSPA+
LTE
IEEE 802
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 802.20
Refers to a family of IEEE standards dealing
with local area networks and metropolitan area
networks
 The services and protocols specified in IEEE 802
map to the lower two layers

Data Link
 Logical Link Control (LLC)
 Media Access Control (MAC)
 Physical

IEEE 802 Standards
WWAN / WMAN / WLAN / WPAN
Note: NFC (Near Field Communication)
A short-range high frequency wireless
communication technology which enables the
exchange of data between devices over about a 10
centimetre (around 4 inches) distance
 The technology is a simple extension of the
ISO/IEC 14443 proximity-card standard
(contactless card, RFID) that combines the
interface of a smartcard and a reader into a
single device

An NFC device can communicate with both
existing ISO/IEC 14443 smartcards and readers,
as well as with other NFC devices, and is thereby
compatible with existing contactless
infrastructure already in use for public
transportation and payment
 NFC technology is currently mainly aimed at
being used with mobile phones


Three main use cases for NFC
 card emulation: the NFC device behaves like
an existing contactless card
 reader mode: the NFC device is active and
read a passive RFID tag, for example for
interactive advertising
 P2P mode: two NFC devices are
communicating together and exchanging
information

Applications
 Mobile ticketing in public transport — an
extension of the existing contactless
infrastructure
 Mobile payment — the device acts as a debit/
credit payment card
 Smart poster — the mobile phone is used to
read RFID tags on outdoor billboards in order
to get info on the move
 Bluetooth pairing — pairing of Bluetooth
devices with NFC bringing them close together
and accepting the pairing

Other applications
 Electronic ticketing — airline tickets,
concert/event tickets, and others
 Electronic money
 Travel cards
 Identity documents
 Mobile commerce
 Electronic keys — car keys, house/office keys,
hotel room keys, etc.
 NFC can be used to configure and initiate
other wireless network connections such as
Bluetooth, Wi-Fi or Ultra-wideband
IEEE 802.11 Standard and Amendments
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
IEEE 802.11 - The WLAN standard was original 1 Mbit/s and 2
Mbit/s, 2.4 GHz RF and infrared [IR] standard (1997), all the
others listed below are Amendments to this standard, except for
Recommended Practices 802.11F and 802.11T.
IEEE 802.11a - 54 Mbit/s, 5 GHz standard (1999, shipping
products in 2001)
IEEE 802.11b - Enhancements to 802.11 to support 5.5 and 11
Mbit/s, 2.4 GHz (1999)
IEEE 802.11c — Bridge operation procedures; included in the
IEEE 802.1D standard (2001)
IEEE 802.11d - International (country-to-country) roaming
extensions (2001)
IEEE 802.11e - Enhancements: QoS, including packet bursting
(2005)
IEEE 802.11f - Inter-Access Point Protocol (2003) Withdrawn
February 2006
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 802.20


IEEE 802.11g - 54 Mbit/s, 2.4 GHz standard (backwards
compatible with b) (2003)
IEEE 802.11h - Spectrum Managed 802.11a (5 GHz) for European
compatibility (2004)

IEEE 802.11i - Enhanced security (2004)

IEEE 802.11j - Extensions for Japan (2004)
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IEEE 802.11-2007 - A new release of the standard that includes
amendments a, b, d, e, g, h, i & j. (July 2007)
IEEE 802.11k - Radio resource measurement enhancements
(2008)
IEEE 802.11n - Higher throughput improvements using MIMO
(multiple input, multiple output antennas) (September 2009)
IEEE 802.11p - WAVE — Wireless Access for the Vehicular
Environment (such as ambulances and passenger cars) (working
— June 2010)
IEEE 802.11r - Fast roaming Working "Task Group r" - (2008)
IEEE 802.11s - Mesh Networking, Extended Service Set (ESS)
(working — September 2010)
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

IEEE 802.11T — Wireless Performance Prediction (WPP) - test
methods and metrics Recommendation cancelled
IEEE 802.11u - Interworking with non-802 networks (for
example, cellular) (working — September 2010)
IEEE 802.11v - Wireless network management (working — June
2010)

IEEE 802.11w - Protected Management Frames (September 2009)
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IEEE 802.11y - 3650-3700 MHz Operation in the U.S. (2008)
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IEEE 802.11z - Extensions to Direct Link Setup (DLS) (August
2007 - December 2011)
IEEE 802.11aa - Robust streaming of Audio Video Transport
Streams (March 2008 - June 2011)
IEEE 802.11mb — Maintenance of the standard. Expected to
become 802.11-2011. (ongoing)
IEEE 802.11ac - Very High Throughput < 6 GHz (September 2008
- December 2012)
IEEE 802.11ad - Extremely High Throughput 60 GHz (December
2008 - December 2012)
IEEE 802.11 / Wi-Fi [/ˈWaɪFaɪ/]
Wireless Fidelity (無線相容性認證)
 A wireless-technology brand owned by the Wi-Fi
alliance
 Promotes standards with the aim of
 improving the interoperability of wireless local
area network products based on the IEEE 802.11
standards

 Common


Internet and VoIP phone access, gaming
network connectivity for consumer electronics
such as televisions, DVD players, and digital
cameras
 Wi-Fi


applications for Wi-Fi
Alliance
a consortium of separate and independent
companies
agrees on a set of common interoperable
products based on the family of IEEE 802.11
standards
IEEE 802.11 Infrastructure Mode

Uses fixed base stations (infrastructure) which
are responsible for coordinating communication
between the mobile hosts (nodes)
IEEE 802.11 Ad Hoc Mode

Mobile nodes communicate with each other
through wireless medium without any fixed
infrastructure
Mobile Ad Hoc Networks (MANET)
Host moves frequently
 Topology changes frequently

A
B
B
A
No cellular infrastructure
 Multi-hop wireless links
 Data must be routed via intermediate nodes

802.11 /11a/11b/11g/11n
IEEE 802.11n

Improve network throughput over 802.11a and
802.11g


with a significant increase in the maximum raw data
rate from 54 Mbit/s to 600 Mbit/s with the use of four
spatial streams at a channel width of 40 MHz
In spatial multiplexing
a high rate signal is split into multiple lower rate
streams
 each stream is transmitted from a different transmit
antenna in the same frequency channel


802.11n uses MIMO (Multiple Input Multiple
Output)
Analog Front End
duplication
Analog Front End
duplication
Signal 1
ADC&
Tx/Rx
Wireless
High Data Transmitter
Rate
ADC&
Tx/Rx
ADC&
Tx/Rx
Signal 2
ADC&
Tx/Rx
Basic two-antenna MIMO system with two-stream
SDM(Spatial Division Multiplexing) example
Wireless
Receiver
High Data
Rate
IEEE 802.11p (VANET) – Motivation
Vehicular Ad hoc NETwork (VANET)
 Safety



on US highways (2004)
 42,800 fatalities, 2.8 million injuries
 ~$230.6 billion cost to society
Efficiency
traffic jams waste time and fuel
 in 2003, US drivers lost a total of 3.5 billion hours
and 5.7 billion gallons of fuel to traffic congestion


Profit

safety features and high-tech devices have become
product differentiators

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VANET-based Emergency Vehicle Warning System
http://www.youtube.com/watch?v=yqtLvZrz2qE
Ford's "Talking" Vehicles - Car-to-Car Communication
Demo
http://www.youtube.com/watch?v=XBqCAVwQv0E
BMW Car-to-X Communication
http://www.youtube.com/watch?v=JzgwlXzO6v0
InfoFueling network
http://www.youtube.com/watch?v=Cc19mcnzvpE
* Ford Demonstrates Vehicle-to-Vehicle Communication for
Increased Safety
http://www.youtube.com/watch?v=RrCyl6pOAC0
What is VANET?

Components in a VANET
 Moving vehicles with On-Board Unit (OBU)
 Road Side Units (RSU)
 local broadcasting information
 IEEE 802.11 access point
RSU
RSU
On-Board Unit (OBU)

Vehicle OBU
WinXP devices
 Windows mobile PDAs
 GPS tracker without user interface
 Text-based OBUs
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
Pedestrian OBU
GPS phone
 Personal tracker

Smart Vehicle
Event data recorder (EDR)
Forward radar
Positioning system
Communication
facility
Rear radar
Display
Computing platform
A modern vehicle is a network of sensors/actuators on wheels !
VANET Architecture
Differences between VANET and MANET
VANETs
MANETs
Highly mobile nodes moving in the
same or opposite directions
Nodes move randomly
Network shape can be best described
by either a one-dimensional line or a
strip
A square or torus shape
With location information and map
Without location information
Rely heavily on broadcast transmission
to disseminate traffic related
information to all reachable nodes
(one to all & all to all)
A query for a route to a certain host
(one to one & one to all)
Energy supported by car
Energy supported by battery
(Energy conservation)
Emergency
Non-emergency
Topology changes frequently
Topology changes slowly
Vehicle Communication (VC)

VC promises safer roads

… more efficient driving

… more fun
VANET – Applications
Congestion detection
 Vehicle platooning
 Road conditions warning
 Collision alert
 Stoplight assistant
 Emergency vehicle warning
 Deceleration warning
 Toll collection
 Border clearance
 Adaptive cruise control
 Drive-through payment
 Merge assistance

A Taxonomy of Vehicular
Communication Systems
Communication Types

Roadside-to-Vehicle Communications (RVC)

Inter-Vehicle Communications (IVC)

Hybrid-Vehicle Communications (HVC)
+
INTER-VEHICLE COMMUNICATION (IVC) SYSTEMS
•
•
Completely infrastructure-free
Only onboard units (OBUs) are needed
IVC SYSTEMS
•
•
SIVC (Single-hop Inter-Vehicle Communication)
• applications of short-range communications
• e.g., lane merging, automatic cruise control
MIVC (Multihop Inter-Vehicle Communication)
• applications of long-range communications
• e.g., traffic monitoring
(a) SIVC
(b) MIVC
ROADSIDE-TO-VEHICLE COMMUNICATION (RVC)
SYSTEMS
•
•
Communication between roadside infrastructure
(RSU) and OBU
Two types of infrastructures
• Sparse RVC (SRVC) system
• Ubiquitous RVC (URVC) system
RVC SYSTEMS - SRVC
•
•
Provide communication services at hot spots
Examples
• a busy intersection scheduling its traffic light
• a gas station advertising its existence (and prices)
• parking availability at an airport
RVC SYSTEMS - URVC
•
•
Provide all roads with high-speed communication
Require considerable investments for providing
full (even significant) coverage of existing
roadways
HYBRID VEHICULAR COMMUNICATION (HVC) SYSTEMS
•
•
Extend the transmission range of RVC systems
Vehicles communicate with roadside
infrastructure even when they are not in direct
wireless range by using other vehicles as mobile
routers
HVC – Adv. & Disadv.
•
•
Advantage
• less roadside infrastructure
Disadvantage
• network connectivity may not be guaranteed in
scenarios with low vehicle density
Vehicular Ad Hoc Network (VANET)

Message propagates to destination using a number of
intermediate links

If vehicle mobility causes links to break, message
rerouted using a different path
Challenges
Physical layer
 limited bandwidth
 Link layer
 congestion control, latency, throughput,
fairness and scalability
 Network (routing) layer
 rapid topology changes and network
fragmentation

WAVE (IEEE 1609) / DSRC (802.11P)
WAVE
(WIRELESS ACCESS IN VEHICULAR ENVIRONMENTS)
WAVE
•
•
•
•
IEEE 1609
Mode of operation used by IEEE 802.11 devices to
operate in the DSRC band (5.850-5.925 GHz)
Defines
• architecture
• communications model
• management structure
• security and physical access
Primary architecture components are OBU, RSU, and
WAVE interface
VAVE Standard Components
•
•
•
•
P1609.1 Resource Manager
P1609.2 Security Services for Applications and
Management Messages
P1609.3 Networking Services
P1609.4 Multi-Channel Operations
WAVE (IEEE 1609) / DSRC (802.11P)
DSRC
(DEDICATED SHORT RANGE COMMUNICATIONS)
•
•
•
•
•
ASTM Standard E2213-03, based on IEEE 802.11a
Name of the 5.9 GHz Band allocated for the ITS
communications
5.855-5.925 GHz range
• divided into 7 licensed channels (each 10 MHz)
Short range radio
• 300m (1000m max)
High data rate
• 6-27 Mbps
ASTM: American Society for Testing and Materia
•
•
•
•
Half-duplex
• station can only send or transmit, but not both at the
same time
Latency
• 200 μs
Communication modes
• vehicle to roadside & vehicle to vehicle
DSRC devices
• IEEE 802.11 systems using the WAVE mode of
operation in the DSRC band
IEEE 802.11p Basis
•
•
•
•
Based on ASTM Standard E2213-03
IEEE 802.11a PHY: OFDM modulation
IEEE 802.11 MAC: CSMA/CA
IEEE 802.11e MAC enhancement: message
prioritization
IEEE 802.11p Requirements
•
•
•
•
•
Longer ranges of operation (up to ~1000 meters)
High speed vehicles (up to ~500 km/h)
Extreme multipath environment (many reflections with
long delays)
Need multiple overlapping ad-hoc networks to operate
with extremely high quality of service
Support automotive applications (e.g. reliable broadcast)
IEEE 802.11p Multi-Channel
•
•
Control Channel (CCH)
• broadcast communication
• dedicated to short, high-priority, data and management
frames
• safety-critical communication with low latencies
• initialization of two-way communication on SCH
Service Channel (SCH)
• two-way communication between RSU and OBU or
between OBUs
• specific applications, e.g. tolling, internet access
• different kinds of applications can be executed in
parallel on different service channels
DSRC CHANNEL ALLOCATION
7 licensed channels (each 10 MHz)
DSRC CHANNEL ALLOCATION
DSRC
HOW DSRC WORKS?
•
•
RSU
• announces to OBUs 10 times per second the
applications it supports
OBU
• listens on channel 172
• authenticates RSU digital signature
• executes safety apps first
• then, switches channels
• executes non-safety apps
• returns to channel 172 and listens
IEEE 1609.4 EXTENSION FOR MULTI-CHANNEL
COORDINATION
CHANNEL COORDINATION
•
•
•
Each Universal Time Coordinated (UTC) second is split into 10
Sync Intervals (each 100ms)
Every Sync Interval is composed of alternating
• CCH Interval (50ms): all WAVE devices have to monitor the
CCH
• SCH Interval (50ms): nodes may switch to a SCH (RX or TX)
Synchronization is performed via GPS
IEEE 802.11P MEDIA ACCESS CONTROL (MAC)
•
•
•
Based on Distributed Control Function (DCF) with
CSMA/CA
CSMA/CA
• if the channel is sensed busy before transmission
then the transmission is deferred for a random
interval
Basic access mode and RTS/CTS mode are used on
SCH
DCF: BASIC ACCESS MODE
•
•
•
•
A node transmits a DATA packet if it senses the channel to
be idle
The receiver
• upon receiving an error-free packet, returns an ACK
The sender
• if the transmitting node does not get an ACK back, it
enters into back-off and retransmits after the back-off
period
Basic access mode suffers from hidden node problem
HIDDEN NODE PROBLEM
•
•
•
A is sending to B
C is ready to transmit to B
• it does not detect carrier and thus begins
transmission
• this produces a collision at B
C’s carrier sense did not provide the necessary
information since station A was hidden from it
A
B
C
RTS/CTS solves the hidden terminal problem!
DCF: RTS/CTS MODE
•
When a node A wants to send a packet to node B, it
initially sends a Request-to-Send (RTS)
A
•
Upon correctly receiving the RTS, node B
responds with Clear-to-Send (CTS)
B
•
After receiving the CTS, node A sends the DATA
packet to node B
A
B
•
•
If node B receives the DATA packet correctly, it
sends an Acknowledgment (ACK) back to node A
Any node that hears an RTS or a CTS is
prohibited from transmitting any signal for a
period that is encoded in the duration field of the
received RTS or CTS
•
•
The duration fields in RTS and CTS are set such that nodes
A and B will be able to complete their communication
within the prohibited period (Network Allocation Vector,
NAV)
Finally, if a node does not get a response to an RTS or a
DATA packet, it enters into an exponential backoff mode

The dark bars below node C and D indicates their NAV
BACKOFF INTERVAL
•
•
•
•
•
When channel is busy, choose a backoff interval in the
range [0, cw]
Count down the backoff interval when medium becomes
idle
Count down is suspended if medium becomes busy again
When backoff interval reaches 0, transmit RTS
Binary exponential backoff in 802.11 DCF
• when a node fails to receive CTS, cw is doubled up (up
to an upper bound, cwmax)
• when a data transfer completes successfully, cw is
reset to cwmin
IEEE 802.11P MAC CHANNEL ACCESS
IEEE 802.15
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 802.20
The 15th working group of the IEEE 802 and
specializes in Wireless PAN (Personal Area
Network) standards
 IEEE 802.15.1


IEEE 802.15.1-2002


a Wireless PAN standard based on Bluetooth
v1.1 specifications including a media access
control and physical layer specification
IEEE 802.15.1-2005

based upon the additions incorporated into
Bluetooth v1.2
the IEEE Study Group discontinues their relationship
with the Bluetooth SIG (the later versions of Bluetooth
will not become future IEEE standards)
 Bluetooth specifications
 Bluetooth 1.0 and 1.0B
 Bluetooth 1.1
 Bluetooth 1.2 (data rate: 1Mbps)
[not IEEE standard]
 Bluetooth 2.0 + EDR (Extended Data Rate)
 Bluetooth 2.1 + EDR (data rate: 3Mbps)
 Bluetooth 3.0 + HS (High Speed) (data rate: perhaps
24Mbps)
 Bluetooth V4.0 (Ble; Bluetooth low energy) (data rate:
perhaps 24Mbps)

IEEE 802.16 Standards (WiMAX)
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 802.20
802.16 WiMAX (Worldwide Interoperability for
Microwave Access，微波存取全球互通)
WirelessMAN
 A telecommunications technology aimed at
 providing wireless data over long distances in
a variety of ways, from point-to-point links to
full mobile cellular type access
 Enable the delivery of last mile wireless
broadband access as an alternative to cable and
DSL

Intel WiMAX Vision
82
WiMAX for Fixed and Mobile Access
83
CPE (Customer Premise Equipment)：即客戶端/用戶端設備
WiMAX Consumer Last Mile
84
WiMAX Backhaul for Business
85
WiMAX Nomadic / Portable
86
2008.11.13 HTC Max 4G
第一支GSM / WiMAX手機俄羅斯發表
88
IEEE 802.16 Operation Modes / Topologies
Point to MultiPoint (PMP) / star topology
 Mesh mode / mesh topology
 Mobile Multihop Relay (MMR) / tree topology

IEEE 802.16 Entities


90

BS – Base Station
 central role in PMP mode
 coordination role in resource
management
 connection/gateway point to other
networks (backhaul, core IP, Internet)
SS – Subscriber Station
 fixed station
 MS – mobile station
 MSS - Multiple Subscriber Station
(playing role of an AP for LAN/WLAN)
 in-door or out-door
RS – Relay station
 used in Mobile Multihop Relay (MMR)
802.16 Relevant Standards

91

802.16d (2004) basic fixed modestandard
 PMP / mesh modes, 70 Mbps
802.16e (2005) (Mobile WiMAX)
 lower data rate, 15 Mbps
 full nomadic and mobile use
including handover
 enhancements to 802.16-2004
 better support for QoS
 scalable OFDMA
 supports devices : mobile smart
phones, PDAs, notebooks, laptops

93
802.16j Mobile Multihop Relay
(MMR)
 enhance the normal PMP frame
structure
 backward compatible with PMP
mode
 new relay networking protocols
 multi-hop relay connections
between SS/MS and BS
 coverage extensions
 throughput enhancement
 actually not mesh mode but
tree topology

94
802.16m
 amendment for advanced air interface
 based on IEEE 802.16e-2005
 expected data rates
 100 Mbps for mobile applications
 1 Gbps for fixed applications
 spectral efficiency, improve voice
capacity, reduce latency
 support for location-based services
 improve multicast broadcast services
IEE 802.16 Relevant Standards Evolution
95
Mobile WiMAX (IEEE 802.16e)
To enable low-cost mobile Internet applications
 To realize the convergence of mobile and fixed
broadband access in a single air interface and
network architecture

96
Mobile WiMAX enabling a variety of usage models in the same network
Mobile WiMAX Technology and
Network Evolution Roadmap
WiMAX Network Reference Model
WiMAX Logical Network Entities

Mobile Station (MS)
 generalized user equipment set providing wireless
connectivity between a single or multiple hosts and the
WiMAX network
 in this context the term MS is used more generically to
refer to both mobile and fixed device terminals

Access Service Network (ASN)


a complete set of network functions required to provide radio
access to MS
 layer 2 (L2) connectivity with the MS according to IEEE
802.16 standards and WiMAX system profile
 transfer of authentication, authorization, and accounting
(AAA) messages to the home network service provider
(HNSP)
 preferred NSP discovery and selection
 relay functionality for establishing layer 3 (L3) connectivity
with MS (i.e., IP address allocation)
 radio resource management
to enable mobility, the ASN may also support ASN and CSN
anchored mobility, paging and location management, and
ASN-CSN tunneling


Base station (BS)
 primarily consists of radio related functions of an
ASN interfacing with an MS over-the-air link
according to MAC and PHY specifications
ASN gateway (ASN-GW)
 an aggregation of centralized functions related to
QoS, security, and mobility management for all the
data connections served by its association with BSs
through R6
 hosts functions related to IP layer interactions with
CSN through R3
 interacts with other ASNs through R4 in support of
mobility

Connectivity Service Network (CSN)
 a set of network functions that provide IP connectivity
services to WiMAX subscriber(s)
 the CSN may further comprises network elements such
as routers, AAA proxy /servers, home agent, and user
databases as well as interworking gateways or
enhanced network servers to support multicast and
broadcast services and location-based services

key functions
IP address management
 AAA proxy or server
 QoS policy and admission control based on user
subscription profiles
 ASN-CSN tunneling support
 subscriber billing and interoperator settlement
 inter-CSN tunneling for roaming
 CSN-anchored inter-ASN mobility
 connectivity to Internet and managed WiMAX services such
as IP multimedia services (IMS), location-based services,
peer-to-peer services, and broadcast and multicast services
 over-the-air activation and provisioning of WiMAX devices

WiMAX Reference Points
R1：SS/MS與ASN間的實體空氣介面
上的通訊協定，為802.16e所定義

R2：SS/MS與CSN間的通訊協定與程
序，用以認證、授權服務和IP設定管
理，此為邏輯路徑

R3：ASN與CSN間的流程協定，支援
AAA決策和行動管理能力

R4：不同ASN間的協定，負責行動管
理，包含控制和乘載資料

R5：不同CSN間互連的協定，包含
AAA、Billing之資料交換

R6：BS與ASN間的協定，包含控制和
乘載資料協定的流程，負責溝通BS與
ASN閘道器的路徑

R8：不同BS間的協定，確保快速換
手，可允許基地台間資料流暫時的流
通
105

WiMAX Network uses IP Based Simple
Protocol Structure
SS/MS
CSN
ASN
BS
ASN-GW
MAC / PHY Protocol Structure in Mobile
WiMAX Release 1.0
WiMAX MAC Layer
(IEEE Std. 802.16-2004)
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Service Specific Convergence Sublayer (CS)
 提供外部網路與MAC之間的對映
 MAC層可透過CS的服務存取點(Service Access Point，SAP)接收外部網
路的資料
 在IEEE 802.16-2004中，進入每個sub-layer但尚未處理的資料稱為服務資料單
元(SDU)，而經過該sub-layer處理後形成特定格式的資料則稱為協定資料單
元(PDU)
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Common Part Sublayer (CPS)
 CPS是MAC層的核心部份，包括媒體存取控制、頻寛分配、連線建立和維
護都是由這個sublayer負責
 CPS通過MAC SAP接收來自各種CS層的資料並對接收的資料實施QoS控制
 若無特別說明，一般所說的802.16 MAC層就是指MAC CPS
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Security Sublayer (SS)
 提供認證、安全的Key交換和加/解密功能
WiMAX Network Architecture and Evolution
(Release 1.0)
ASN and CSN mobility (for mobility support)
 Paging and location management
 IPv4 and IPv6 connectivity
 Preprovisioned/static QoS
 Optional radio resource management (RRM)
 Network discovery/selection
 IP/Ethernet CS support
 Flexible credentials, pre- and postpaid accounting
 Roaming (RADIUS only)
 3GPP I-WLAN compatible interworking
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WiMAX Network Architecture and Evolution
(Release 1.5)
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Over-the-air (OTA) activation and provisioning
Location-based services (LBS)
Multicast broadcast service (MBS)
IMS integration
Dynamic QoS and policy and charging (PCC) compatible
with 3GPP Release 7
Telephony VoIP with emergency call services and lawful
interception
Full NAP sharing support
Handover data integrity
Multihost support
Ethernet services, VLAN
Enhanced open Internet services
Diameter-based AAA
WiMAX Network Architecture and Evolution
(Release 2.0)
 Multimedia
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session continuity
 3GPP/2 interworking (optimized handover
)
 Network management, including selforganized /optimized networks (SONs)
 Seamless WiFi-WiMAX handover
 Roaming enhancements
 Support for multihop relay stations
 Support for femto-cells
 Device reported metrics
802.20 MBWA
(Mobile Broadband Wireless Access)
IEEE 802.11
IEEE 802.15
IEEE 802.16
IEEE 802.20
 IEEE
802.20 or Mobile Broadband Wireless
Access (MBWA)
an IEEE Standard to enable worldwide deployment
of multi-vendor interoperable mobile broadband
wireless access networks
 a packet-based air interface designed for IP-based
services
 low-cost, always-on, and mobile broadband wireless
networks, nicknamed as Mobile-Fi
 the goals of 802.20 and 802.16e, the so-called "mobile
WiMAX", are similar
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 Technical
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description
IP roaming & handoff (more than 1 Mbps)
new MAC and PHY with IP and adaptive
antennas
optimized for full mobility up to vehicular speeds
of 250 km/h
operates in licensed bands (below 3.5 GHz)
utilizes packet architecture
low latency
WWAN / WMAN / WLAN / WPAN