Moise Effo IEEE 80216 Overview IEEE 80216e Protocol Stack Network architecture The Mobile Wimax adopts Orthogonal Frequency Division Multiple Access OFDMA for improved multipath performance in nonlineofsight environments by ID: 512870
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Slide1
IEEE 802.16e/Mobile WiMAX
Moise
EffoSlide2
IEEE 802.16 OverviewSlide3
IEEE 802.16e Protocol StackSlide4
Network architectureSlide5
The Mobile
Wimax
adopts Orthogonal Frequency Division Multiple Access (OFDMA) for improved multi-path performance in non-line-of-sight environments by:
Multiplexing operation of data streams from multiple users
Dynamically assign a subset of sub-channels to individual users.
Scalable OFDMA (SOFDMA) is introduced in the IEEE 802.16e an amendment to support scalable channel bandwidths from 1.25 to 20
MHz.
Scalability is supported by adjusting the FFT size while fixing the sub-carrier frequency spacing at 10.94 kHz.
PHYSICAL Layer DescriptionSlide6
Since the resource unit sub-carrier bandwidth and symbol duration is fixed, the impact to higher layers is minimal when scaling the bandwidth.
802.16e systems offer scalability in both radio access technology and network architecture, thus providing a great deal of flexibility in network deployment options and service offerings.
802.16e supports TDD and Full and Half-Duplex FDD operation.
PHYSICAL Layer DescriptionSlide7
Adaptive modulation and coding (AMC)
is the matching of the modulation, coding and signal strength and protocol parameters to the conditions on the radio link.
Hybrid Automatic Repeat Request (HARQ)
is a combination of high-rate forward error-correcting coding (FEC), and ARQ (Automatic Repeat-
reQuest
) error-control for detectable-but-uncorrectable errors.
Fast Channel Feedback (CQICH)
is a method of communicating feedback information between a mobile station and a base station by determining a need to request bandwidth allocation.
PHYSICAL Layer DescriptionSlide8
MAC Layer Description
Quality of service (
QoS
)
is provided via service flows. This is a unidirectional flow of packets that is provided with a particular set of
QoS
parameters
Service
Definition
Typical Applications
QoS
Specifications
Unsolicited Grant Service (UGS)
Real-time data streams comprising fixed-size data packets issued at periodic intervals.
T1/E1 transport, VoIP without silence suppression.
-Maximum Sustained Rate
-Maximum Latency
Tolerance
-Jitter Tolerance
Extended Real-time Polling Service (ErtPS)
Real-time service flows that generate variable-sized data packets on a periodic basis.
VoIP with silence suppression.
-Minimum Reserved Rate
-Maximum Sustained Rate
-Maximum Latency
Tolerance
-Jitter Tolerance
-
Traffic Priority
Real-time Polling Service (rtPS)
Real-time data streams comprising variable-sized data packets that are issued at periodic intervals.
MPEG Video.
-Minimum Reserved Rate
-
Maximum Sustained Rate
-
Maximum Latency
Tolerance
-
Traffic Priority
Non-real-time Polling Service (nrtPS).
Delay-tolerant data streams comprising variable-sized data packets for which minimum data rate is required.
FTP with guaranteed minimum throughout.
-Minimum Reserved Rate
-
Maximum Sustained Rate
-
Traffic Priority
Best Effort (BE)
Data streams for which no minimum service level is required and therefore may be handled on a space-available basis.
HTTP.
-Maximum Sustained Rate
-
Traffic PrioritySlide9
MAC Layer Description
Scheduling service
is designed to efficiently deliver broadband data services including voice, data, and video over time-varying broadband wireless channel. The MAC scheduling service has the following properties that enable the broadband data service:
Fast Data Scheduler
Scheduling for both DL and UL
Dynamic Resource Allocation
QoS
Oriented
Frequency Selective SchedulingSlide10
MAC Layer Description
Mobility management
Power management
Mobile
Wimax
supports the two modes for power efficient operation:
- Sleep Mode
- Idle Mode
Handoff there are handoffs methods supported by the mobile
Wimax
:
- Hard Handoff (HHO)
- Fast Base Station Switching (FBSS)
- Macro Diversity Handover (MDHO)Slide11
Security
Key Management Protocol
for Traffic Encryption Control, Handoff Key Exchange and Multicast/Broadcast security messages.
Device/User Authentication
by providing support for credential that are SIM-based.
Traffic Encryption
, a cipher is used for the protection all the user data over the Mobil Wimax MAC interface. (AES-CCM)
Control Message Protection
using AES Based CMAC.
Fast Handover Support
there is a 3-way Handshake scheme to optimize the re-authentication mechanisms for fast handovers.
MAC Layer DescriptionSlide12
Advanced features of mobile wimax
Smart antenna technologies:
typically involve complex vector or matrix operations on signals due to multiple antennas. OFDMA allows smart antenna operations to be performed on vector-flat sub-carriers. Complex equalizers are not required to compensate for frequency selective fading.
Mobile
Wimax
supports a full range of smart antenna technologies to enhance system performance.
Beamforming
for a better coverage and capacity of the system and reduce outage probability.Space-Time Code(STC)
transmit diversity codes are used to provide spatial diversity and reduce fade margin.Slide13
Advanced features of mobile wimax
Smart antenna technologies
Spatial Multiplexing
(SM) is to take advantage of higher peak rates and increases throughput.
multiple streams are transmitted over multiple antennas
both receiver and transmitter must have multiple antennas to achieve higher throughput.
The inclusion of MIMO antenna techniques along with flexible sub-channelization schemes, Advanced Coding and Modulation all enable the802.16e technology to support a high data rate:
•peak DL data rates up to 63 Mbps per sector and
•peak UL data rates up to 28 Mbps per sector
in a 10 MHz channel.Slide14
Advanced features of mobile wimax
Fractional Frequency reuse
All cells/sectors operate on the same frequency channel to maximize spectral efficiency.
Users operate on sub-channels, which only occupy a small fraction of the whole channel bandwidth
The flexible sub-channel reuse is facilitated by sub-channel segmentation and permutation zoneSlide15
Advanced features of mobile wimax
Multicast and Broadcast Service (MBS)
combines the best features of DVB-H,
MediaFLO
and 3GPP
E-UTRA and satisfies the following requirements:
High data rate and coverage using a Single Frequency Network (SFN)
Flexible allocation of radio resources
Low MS power consumption
Support of data-casting in addition to audio and video streams
Low channel switching timeSlide16
Tolerance to Multipath and Self-Interference
Scalable Channel Bandwidth
Orthogonal Uplink Multiple Access
Support for Spectrally-Efficient TDD
Frequency-Selective Scheduling
Fractional Frequency Reuse
Fine Quality of Service (
QoS
)
Advanced Antenna TechnologyKey advantages of Mobile WIMAXSlide17
summarize
Mobile
Wimax
can be considered as a real competitor for 3G for example in IP-traffic(VoIP/ IPTV).
Mobile
Wimax
supports seamless handoff which provides switching between base stations in vehicular speeds.
Mobile
Wimax
uses Scalable OFDMA multiplexing which maximizes the spectral efficiency. Slide18
IEEE 802.16e/Mobile WiMAX
Questions