Dcs Wi Max Protocol
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Dcs Wi Max Protocol as PDF for free.
More details
- Words: 2,661
- Pages: 54
Worldwide Interoperability for Microwave Access ( Wi - MAX) D C Sonkhla, SDE Computer, BRBRAITT
Protocol
Oct 22, 2008
2
Protocol IEEE 802.16 MAC – Highlights Wireless MAN: Point-to-Multipoint and optional mesh topology Connection-oriented Multiple Access: DL TDM & TDMA, UL TDMA;UL OFDMA & TDMA, DL OFDMA & TDMA (Optional)
Oct 22, 2008
3
Protocol PHY considerations that affect the MAC Duplex: TDD, FDD, FDX FDD BS and SS, HDX FDD SS Adaptive burst profiles (Modulation and FEC) on both DL and UL Protocol-independent core (ATM, IP, Ethernet) Flexible QoS offering (CBR, rt-VBR, nrt-VBR, BE) Strong security support Oct 22, 2008
4
IEEE 802.16 -- Introduction Coverage range up to 50km and speeds up to 70Mbps (shared among users).
Oct 22, 2008
5
IEEE 802.16 -- Introduction
Oct 22, 2008
6
IEEE 802.16 MAC – CPS – MAC PDU Concatenation
Multiple MAC PDUs are concatenated into the same PHY burst
MAC PDU 1 HT
FEC
MAC PDU Payload
FEC block 1
PHY Burst (e.g., TDMA burst)
Oct 22, 2008
MAC PDU 2 CRC
HT
FEC Block 2
Preamble
OFDM symbol 1
MAC PDU Payload
FEC Block 3
OFDM symbol 2
MAC PDU k CRC
......
......
......
HT
MAC PDU Payload
CRC
FEC block m
OFDM symbol n
7
IEEE 802.16 MAC – CPS – MAC PDU Fragmentation
A MAC SDU can be fragmented into multiple segments, each segment is encapsulated into one MAC PDU MAC SDU
Fragmentation Sub-Header (8 bits)
HT
FEC
F S H
MAC SDU seg-1 HT
MAC PDU Payload
FEC block 1
Pre.
CRC
......
OFDM symbol 1
FEC Block m1
......
PHY Burst
Oct 22, 2008
MAC SDU seg-2
OFDM symbol n1
F S H
MAC PDU Payload
MAC SDU seg-3 CRC
FEC block 1
Pre.
HT
F S H
MAC PDU Payload
......
OFDM symbol 1
CRC
FEC Block m2
......
OFDM symbol n2
PHY Burst
8
IEEE 802.16 MAC – CPS – MAC PDU Packing
Packing with fixed size MAC SDUs (no packing sub-header is needed) MAC SDU 1
HT
MAC SDU 2
......
MAC SDU k
MAC PDU Payload
Fixed size MSDUs, e.g., ATM Cells, on the same connection
CRC
Packing with variable size MAC SDUs (Packing Sub-Heade is neeeded)
Packing Sub-Heder (16 bits)
HT
Oct 22, 2008
PSH
MAC SDU or seg. 1
MAC SDU or seg n
MAC SDU or seg 2
PSH
Variable size MSDUs or MSDU segments, e.g., IP packets, on the same connection
......
PSH
CRC
9
IEEE 802.16 MAC – CPS QoS
Three components of 802.16 QoS Service flow QoS scheduling Dynamic service establishment Two-phase activation model (admit first, then activate) Service Flow A unidirectional MAC-layer transport service characterized by a set of QoS parameters, e.g., latency, jitter, and throughput assurances Identified by a 32-bit SFID (Service Flow ID) Three types of service flows Provisioned: controlled by network management system Admitted: the required resources reserved by BS, but not active Active: the required resources committed by the BS Oct 22, 2008
10
IEEE 802.16 MAC – CPS – Uplink Service Classes
UGS: Unsolicited Grant Services rtPS: Real-time Polling Services nrtPS: Non-real-time Polling Services BE: Best Effort
Oct 22, 2008
11
IEEE 802.16 MAC – CPS – Uplink Services: UGS
UGS: Unsolicited Grant Services For CBR or CBR-like services, e.g., T1/E1. The BS scheduler offers fixed size UL BW grants on a real-time periodic basis. The SS does not need to send any explicit UL BW req. Oct 22, 2008
12
IEEE 802.16 MAC – CPS – Uplink Services: rtPS
rtPS: Real-time Polling Services For rt-VBR-like services, e.g., MPEG video. The BS scheduler offers realtime, periodic, UL BW request opportunities. The SS uses the offered UL BW req. opportunity to specify the desired UL BW grant. The SS cannot use contentionbased BW req. Oct 22, 2008
13
IEEE 802.16 MAC – CPS – Uplink Services: nrtPS
nrtPS: non-real-time polling services For nrt-VBR-like services, such as, bandwidth-intensive file transfer. The BS scheduler shall provide timely (on a order of a second or less) UL BW request opportunities.
Oct 22, 2008
The SS can use contention-based BW req. opportunities to send BW req.
14
IEEE 802.16 MAC – CPS – Uplink Services: BE
BE: Best Effort For best-effort traffic, e.g., HTTP, SMTP. The SS uses the contentionbased BW request opportunities.
Oct 22, 2008
15
IEEE 802.16 MAC – CPS – Bandwidth Grant
BW grants are per Subscriber Station: Allows realtime reaction to QoS need, i.e., SS may re distribute bandwidth among its connections, maintaining QoS and servicelevel agreements Lower overhead, i.e., less ULMAP entries compare to grant per connection Off loading base station’s work Requires intelligent subscriber station to redistribute the allocated BW among connections
Oct 22, 2008
16
IEEE 802.16 MAC – CPS – BW Request/Grant Mechanisms
Oct 22, 2008
Implicit requests (UGS): No actual requests BW request messages, i.e., BW req. header Sends in either a contentionbased BW req. slot or a regular UL allocation for the SS;he special B Requests up to 32 KB with a single message Request Incremental or aggregate, as indicated by MAC header– Piggybacked request (for non-UGS services only) Presented in Grant Management (GM) sub header in a data MAC PDU of the same UL connection is always incremental Up to 32 KB per request for the CID Poll-Me bit Presented in the GM subheader on a UGS connection
17
IEEE 802.16 MAC – CPS -- Contention UL Access
Two types of Contention based UL slots Initial Ranging Used for new SS to join the system Requires a long preamble
BW Request Used for sending BW req Short preamble
Collision Detection and Resolution Detection: SS does not get the expected response in a given time Resolution: a truncated binary exponential backoff window Oct 22, 2008
18
IEEE 802.16 MAC – CPS UL Sub-Frame Structure
Source: http://www.cygnuscom.com/pdf/WP_PN_Article.pdf
Oct 22, 2008
19
IEEE 802.16 MAC – CPS – Ranging
Ranging is a process of acquiring the correct timing offset, and PHY parameters, such as, Tx power level, frequency offset, etc. so that the SS can communicate with the BS correctly. BS performs measurements and feedback. SS performs necessary adjustments. Two types of Ranging: Initial ranging: for a new SS to join the system Periodic ranging (also called maintenance ranging): dynamically maintain a good RF link. Oct 22, 2008
20
IEEE 802.16 MAC – CPS – Automatic Repeat reQuest (ARQ)
A Layer-2 sliding-window based flow control mechanism. Per connection basis. Only effective to non-real-time applications. Uses a 11-bit sequence number field. Uses CRC-32 checksum of MAC PDU to check data errors. Maintain the same fragmentation structure for Retransmission. Optional.
Oct 22, 2008
21
IEEE 802.16 MAC – Privacy Sub-layer (PS)
Two Major Functions: Secures over-the-air transmissions Protects from theft of service
Two component protocols: Data encryption protocol A client/server model based Key management protocol (Privacy Key Management, or PKM)
Oct 22, 2008
22
IEEE 802.16 MAC – PS -- Security Associations
A set of privacy information, e.g., encryption keys, used encryption algorithm Three types of Security Associations (SAs) Primary SA: established during initial registration Static SA: provisioned within the BS Dynamic SA: dynamically created on the fly
Identified by a 16-bit SAID Connections are mapped to SAs Oct 22, 2008
23
IEEE 802.16 MAC – PS
--
Multi-level Keys and Their Usage
Public Key Contained in X.509 digital certificate Issued by SS manufacturers Used to encrypt AK
Authorization Key (AK) Provided by BS to SS at authorization Used to derive KEK Key Encryption Key (KEK) Derived from AK Used to encrypt TEK Traffic Encryption Key (TEK) Provided by BS to SS at key exchange Used to encrypt traffic data payload Oct 22, 2008
24
IEEE 802.16 MAC – PS -- Data Encryption
Use DES (Data Encryption Standard) in CBC (Cipher Block Chaining) mode with IV (Initialization Vector). CBC IV is calculated from IV parameter in TEK keying info; and PHY synchronization field in DLMAP. Only MAC PDU payload (including sub-headers) is encrypted. MAC PDU headers are unencrypted. Management messages are unencrypted. Oct 22, 2008
25
References
IEEE802.16-2004 Alcatel White Paper: WiMAX, making ubiquitous high-speed data services a reality Intel White Paper: Understanding WiMAX and 3G for Portable/Mobile Broadband Wireless WiMAX Forum: www.wimaxforum.com http://en.wikipedia.org/wiki/WiMax
Oct 22, 2008
26
IEEE 802.16 MAC – commonly used terms
BS – Base Station SS – Subscriber Station, (i.e., CPE) DL – Downlink, i.e. from BS to SS UL – Uplink, i.e. from SS to BS FDD – Frequency Division Duplex TDD – Time Division Duplex TDMA – Time Division Multiple Access TDM – Time Division Multiplexing OFDM – Orthogonal Frequency Division Multiplexing OFDMA - Orthogonal Frequency Division Multiple Access QoS – Quality of Service Oct 22, 2008
27
Application There are two main applications of Wi-MAX • fixed Wi-MAX applications are point-tomultipoint enabling broadband access to homes and businesses • Mobile Wi-MAX offers the full mobility of cellular networks at true broadband speeds. Both fixed and mobile applications of WiMAXare engineered to help deliver ubiquitous, high-throughput broadband wireless services at a low cost. . Oct 22, 2008
28
Application Mobile Wi-MAX is based on OFDMA (Orthogonal Frequency Division Multiple Access) technology which has inherent advantages in throughput, latency, spectral efficiency, and advanced antennae support; ultimately enabling it to provide higher performance than today's wide area wireless technologies. Furthermore, many next generation 4G wireless technologies may evolve towards OFDMA and all IP-based networks as an ideal for delivering cost-effective wireless data services Oct 22, 2008
29
Advantages Wi-MAX can effectively be used for point-to-point backhaul over long distances (up to 30 Miles). Unobstructed, Wi-MAX can span many miles and cover wide areas (up to 30 Miles). 4-6 Miles in non line-of-site applications vs. 150-300 ft for Wi-Fi. This makes it suitable for entire cities and allows development of Metropolitan Area Networks (MANs) versus Local Area Networks for Wi-Fi.
Oct 22, 2008
30
Advantages Wi-MAX promises to be internationally standardized, facilitating large production runs by multiple suppliers, bringing down equipment pricing. Wi-MAX has a higher speed than Wi-Fi and, depending on bandwidth availability, may produce data transmissions of up to 70 Mbps vs. 54 for Wi-Fi.
Oct 22, 2008
31
Advantages Wi-MAX can be used in both Line-of-Sight (LOS), for back-haul applications (up to 30 miles under ideal conditions), and non-LOS network access applications. Wi-MAX can be used to connect multiple network hot spots, and provide last-mile connectivity directly to the home or business. Wi-MAXcan use licensed or unlicensed spectrum.
Oct 22, 2008
32
Advantages Wi-MAX is symmetrical in most cases providing the same throughput upstream and downstream Since Wi-MAX does not use the Medium Voltage power lines for transport, the Radio Frequency Interference caused by signal transport over the Medium Voltage system.
Oct 22, 2008
33
WiMax Management Information Base (MIB).
Oct 22, 2008
34
WiMAX Mission Statement
The purpose of WiMAX is to promote deployment of broadband wireless access networks by using a global standard and certifying interoperability of products and technologies
Writing test specs Qualifying test labs Certifying products WiMAX is the next revolutionary technology after WiFi
Focus on interoperability Oct 22, 2008
36
IEEE 802.16a/d/e IEEE 802.16a – A Fixed Wireless Access standard
PtMP, connection oriented MAC layer Three Physical layers: OFDM, OFDMA and Single Carrier Approved in April 2003 IEEE 802.16d – now called IEEE 802.16-2004
Approved in July 2004 Focused on fixed applications Consolidates all amendments and base standard for WiMAX IEEE 802.16e – A Mobile Wireless Access standard
Incorporate features and protocols needed for portability/mobility
•
Modes added to enhance portability/mobility performance
HIPERMAN – the parallel H105 ETSI effort Expect final approval • Identical to 802.16a and 802.16d, except: • Only OFDM PHY
Oct 22, 2008
37
WiMAX Vision: Broadband Everywhere
1
3
2 FRACTIONAL BACKHAUL for T1 for SMALL BUSINESS HOTSPOTS
T1+ LEVEL SERVICE ENTERPRISE
Mobile Backhaul
RESIDENTIAL & SoHo DSL LEVEL SERVICE
802.1 6d
802.16 d
WMAN Nomadic Coverage --> handoff fromH HOT H SPOTS H H
802.1 6e
5
4
H
H H
H H = wide area coverage outside of Hot Spots
INTERNET BACKBONE BWA Operator Network Backbone Oct 22, 2008
Mobility 38
Salient features of BSNL WIMAX
WIMAX IN 10 CITIES-
KOLKATA, CHENNA, HYDERABAD, BANGLORE AHMEDABAD, PUNE, HISSAR, ROHTA, PINJORE and KARNAL 150 TYPE 1 CPEs.(3 RJ 45) VENDOR-MOTOROLA, APERTO TECNOLOGY FREQ. ALLOTTED- 2 FDD SPOTS OF 3.5 MHz. FOUR SECTORS 7.5MBPS*4 = 30 MBPS TOTAL NET THROUGHPUT BS CAPACITY-1000CPE,50 SUBSCRIBER/CPE MODEL-PM 5000 BS,PM 300i CPE. BS IS WIMAX CERTIFIED
Oct 22, 2008
39
WIMAX BS
Oct 22, 2008
40
WIMAX CPE components
Oct 22, 2008
41
Management Traffic connected to PE router via 128kbps MLLN circuit & data traffic to Tier-II
NMS Bangalore
1.
User Data is backhauled to the Tier II switch using Ethernet over SDH or relevant media.
2.
Management Data is transported to the PE router using a 128kbps MLLN backhaul.
3.
EMS Client connected to the PE using 128kbps MLLN backhaul
4.
All Management elements are part of a VPN.
EMS Server
City A BTS Location
Provider Router
MPLS CORE Tier I
Provider Router
Tier II
Broadband RAS/ Provider Edge
CPE Locations
Eth over SDH
Tier I
Eth over SDH
User/ Backhaul Data
Tier II EMS Client
Provider Edge Router 128Kbps Managed Leased Line Network
Management Data
Oct 22, 2008
42
Snapshot of Frequency Spectrum for WiMAX (2.3 - 5.8 GHz)
MMDS ~2500-2690 2700-2900
3.5GHz band 3400-3600 3300-3400
Low/Mid UNII-band (802.11a)
US WCS 2305-2320 2345-2360
~5725-5850
5150-5350
ISM (11b/g) 2400-2480
Upper UNII-band
WiMAX profiles available
WRC (new) 5470-5725
Other Bands
Note : WPC has allotted two no of FDD frequencies of 3.5 MHz (1) 3308.75 / 3358.75 MHz (2) 3312.25 / 3362.25 MHz Oct 22, 2008
43
Performance Requirement from WiMax
CPE Performance: 8 Mbps net throughput per sector Shall support 50 subscriber per CPE BSNL has specifically asked for V5.2, G703,Gx interface in BS & POTS, VOIP, USB,G703 interfaces in CPE besides the normal FE interface in BS & CPE. BSNL has given 1 Year time frame to bidder to provide these interfaces since these are not available with any bidders.
Oct 22, 2008
44
APPLICATIONS OF WIMAX
Multiple broadband from a single CPE.(Each subs. With different SLA) Backhaul of wi-fi Backhaul of DSLMP Internet lease line. MPLS VPN sopport.
Oct 22, 2008
45
DSLAM BACKHAUL APPLICATION Up to 20kmts Ethernet
Ethernet CANOPY
CANOPY
CANOPY
Wi-Max BTS DSLAM
Wi-Max CPE
DSLAM Wi-Max CPE Location-2
Location-1 Ethernet Switch
BRAS
Oct 22, 2008
INTERNET BACKBONE 46
Wireless Broadband Application
FIG-2
SME
ENTERPRISE
Wi-Max CPE
Wi-Max CPE
KIOSK CANOPY
CANOPY
CANOPY
Wi-Max Base Station Wi-Fi Access Point
Wi-Max CPE
Wi-Max CPE
Wi-Fi HOTSPOT
INTERNET BACKBONE
Oct 22, 2008
47
BROADBAND SERVICE USING WI-MAX Ethernet Cable Wi-Max CPE Ethernet Switch
Wi-Max Base Station C A NO P Y
C A NO P Y
CANOPY
INTERNET BACKBONE
Oct 22, 2008
48
BROADBAND SERVICE USING WI-FI AND WI-MAX
Wi-Max CPE
Wi-Fi Access Point
Wi-Max Base Station C A NO P Y
C A NO P Y
CANOPY
INTERNET BACKBONE
Oct 22, 2008
49
FIG-5 MPLS-VPN CONNECTIVITY SME
ENTERPRISE
Wi-Max CPE
Wi-Max CPE
SME CANOPY
CANOPY
CANOPY
Wi-Max Base Station SWITCH
MPLS NETWORK
Oct 22, 2008
Wi-Max CPE
INTERNET BACKBONE
50
Combined VoIP, DSL & Wi-Max Solution for URBAN and RURAL Telephony
CO
Local PSTN Cu Pairs
Media Gateway SIP Proxy & Media Server
1 BSNL INTERNET IP
POTS Splitter
10/100B T
Existing Loop Network Voice & Data
SOHO DSL CPE ATA
IP DSLAM BRAS
Aperto Wi-Max Network
Rural Telephony Aperto Wireless Access
2
Oct 22, 2008
2
Wi-Max CPE 1
1
3 Analog 24 port FXS gateway
2 4
51
Issues with WI-MAX Equipment 4. Site survey 5. 5.2/G703 interfaces at CPE & BS end. 6. Height of Antenna at CPE end for longer distance. 7. Upgradation/Replacement to certified equipment.
Oct 22, 2008
52
Issues Issues with Wi-MAX
Upstream Bit Rate, Downstream Bit Rate, Acceptable Outage Time, Security, and Encryption, Video Quality, Internet Speeds, Streaming Video, Bandwidth & Efficiency, Voice over IP, Gaming Encryption, Appropriate Frequency Tolerance to Interference and Gateway Priority - Video Data
Oct 22, 2008
53
THANK YOU
Protocol
Oct 22, 2008
2
Protocol IEEE 802.16 MAC – Highlights Wireless MAN: Point-to-Multipoint and optional mesh topology Connection-oriented Multiple Access: DL TDM & TDMA, UL TDMA;UL OFDMA & TDMA, DL OFDMA & TDMA (Optional)
Oct 22, 2008
3
Protocol PHY considerations that affect the MAC Duplex: TDD, FDD, FDX FDD BS and SS, HDX FDD SS Adaptive burst profiles (Modulation and FEC) on both DL and UL Protocol-independent core (ATM, IP, Ethernet) Flexible QoS offering (CBR, rt-VBR, nrt-VBR, BE) Strong security support Oct 22, 2008
4
IEEE 802.16 -- Introduction Coverage range up to 50km and speeds up to 70Mbps (shared among users).
Oct 22, 2008
5
IEEE 802.16 -- Introduction
Oct 22, 2008
6
IEEE 802.16 MAC – CPS – MAC PDU Concatenation
Multiple MAC PDUs are concatenated into the same PHY burst
MAC PDU 1 HT
FEC
MAC PDU Payload
FEC block 1
PHY Burst (e.g., TDMA burst)
Oct 22, 2008
MAC PDU 2 CRC
HT
FEC Block 2
Preamble
OFDM symbol 1
MAC PDU Payload
FEC Block 3
OFDM symbol 2
MAC PDU k CRC
......
......
......
HT
MAC PDU Payload
CRC
FEC block m
OFDM symbol n
7
IEEE 802.16 MAC – CPS – MAC PDU Fragmentation
A MAC SDU can be fragmented into multiple segments, each segment is encapsulated into one MAC PDU MAC SDU
Fragmentation Sub-Header (8 bits)
HT
FEC
F S H
MAC SDU seg-1 HT
MAC PDU Payload
FEC block 1
Pre.
CRC
......
OFDM symbol 1
FEC Block m1
......
PHY Burst
Oct 22, 2008
MAC SDU seg-2
OFDM symbol n1
F S H
MAC PDU Payload
MAC SDU seg-3 CRC
FEC block 1
Pre.
HT
F S H
MAC PDU Payload
......
OFDM symbol 1
CRC
FEC Block m2
......
OFDM symbol n2
PHY Burst
8
IEEE 802.16 MAC – CPS – MAC PDU Packing
Packing with fixed size MAC SDUs (no packing sub-header is needed) MAC SDU 1
HT
MAC SDU 2
......
MAC SDU k
MAC PDU Payload
Fixed size MSDUs, e.g., ATM Cells, on the same connection
CRC
Packing with variable size MAC SDUs (Packing Sub-Heade is neeeded)
Packing Sub-Heder (16 bits)
HT
Oct 22, 2008
PSH
MAC SDU or seg. 1
MAC SDU or seg n
MAC SDU or seg 2
PSH
Variable size MSDUs or MSDU segments, e.g., IP packets, on the same connection
......
PSH
CRC
9
IEEE 802.16 MAC – CPS QoS
Three components of 802.16 QoS Service flow QoS scheduling Dynamic service establishment Two-phase activation model (admit first, then activate) Service Flow A unidirectional MAC-layer transport service characterized by a set of QoS parameters, e.g., latency, jitter, and throughput assurances Identified by a 32-bit SFID (Service Flow ID) Three types of service flows Provisioned: controlled by network management system Admitted: the required resources reserved by BS, but not active Active: the required resources committed by the BS Oct 22, 2008
10
IEEE 802.16 MAC – CPS – Uplink Service Classes
UGS: Unsolicited Grant Services rtPS: Real-time Polling Services nrtPS: Non-real-time Polling Services BE: Best Effort
Oct 22, 2008
11
IEEE 802.16 MAC – CPS – Uplink Services: UGS
UGS: Unsolicited Grant Services For CBR or CBR-like services, e.g., T1/E1. The BS scheduler offers fixed size UL BW grants on a real-time periodic basis. The SS does not need to send any explicit UL BW req. Oct 22, 2008
12
IEEE 802.16 MAC – CPS – Uplink Services: rtPS
rtPS: Real-time Polling Services For rt-VBR-like services, e.g., MPEG video. The BS scheduler offers realtime, periodic, UL BW request opportunities. The SS uses the offered UL BW req. opportunity to specify the desired UL BW grant. The SS cannot use contentionbased BW req. Oct 22, 2008
13
IEEE 802.16 MAC – CPS – Uplink Services: nrtPS
nrtPS: non-real-time polling services For nrt-VBR-like services, such as, bandwidth-intensive file transfer. The BS scheduler shall provide timely (on a order of a second or less) UL BW request opportunities.
Oct 22, 2008
The SS can use contention-based BW req. opportunities to send BW req.
14
IEEE 802.16 MAC – CPS – Uplink Services: BE
BE: Best Effort For best-effort traffic, e.g., HTTP, SMTP. The SS uses the contentionbased BW request opportunities.
Oct 22, 2008
15
IEEE 802.16 MAC – CPS – Bandwidth Grant
BW grants are per Subscriber Station: Allows realtime reaction to QoS need, i.e., SS may re distribute bandwidth among its connections, maintaining QoS and servicelevel agreements Lower overhead, i.e., less ULMAP entries compare to grant per connection Off loading base station’s work Requires intelligent subscriber station to redistribute the allocated BW among connections
Oct 22, 2008
16
IEEE 802.16 MAC – CPS – BW Request/Grant Mechanisms
Oct 22, 2008
Implicit requests (UGS): No actual requests BW request messages, i.e., BW req. header Sends in either a contentionbased BW req. slot or a regular UL allocation for the SS;he special B Requests up to 32 KB with a single message Request Incremental or aggregate, as indicated by MAC header– Piggybacked request (for non-UGS services only) Presented in Grant Management (GM) sub header in a data MAC PDU of the same UL connection is always incremental Up to 32 KB per request for the CID Poll-Me bit Presented in the GM subheader on a UGS connection
17
IEEE 802.16 MAC – CPS -- Contention UL Access
Two types of Contention based UL slots Initial Ranging Used for new SS to join the system Requires a long preamble
BW Request Used for sending BW req Short preamble
Collision Detection and Resolution Detection: SS does not get the expected response in a given time Resolution: a truncated binary exponential backoff window Oct 22, 2008
18
IEEE 802.16 MAC – CPS UL Sub-Frame Structure
Source: http://www.cygnuscom.com/pdf/WP_PN_Article.pdf
Oct 22, 2008
19
IEEE 802.16 MAC – CPS – Ranging
Ranging is a process of acquiring the correct timing offset, and PHY parameters, such as, Tx power level, frequency offset, etc. so that the SS can communicate with the BS correctly. BS performs measurements and feedback. SS performs necessary adjustments. Two types of Ranging: Initial ranging: for a new SS to join the system Periodic ranging (also called maintenance ranging): dynamically maintain a good RF link. Oct 22, 2008
20
IEEE 802.16 MAC – CPS – Automatic Repeat reQuest (ARQ)
A Layer-2 sliding-window based flow control mechanism. Per connection basis. Only effective to non-real-time applications. Uses a 11-bit sequence number field. Uses CRC-32 checksum of MAC PDU to check data errors. Maintain the same fragmentation structure for Retransmission. Optional.
Oct 22, 2008
21
IEEE 802.16 MAC – Privacy Sub-layer (PS)
Two Major Functions: Secures over-the-air transmissions Protects from theft of service
Two component protocols: Data encryption protocol A client/server model based Key management protocol (Privacy Key Management, or PKM)
Oct 22, 2008
22
IEEE 802.16 MAC – PS -- Security Associations
A set of privacy information, e.g., encryption keys, used encryption algorithm Three types of Security Associations (SAs) Primary SA: established during initial registration Static SA: provisioned within the BS Dynamic SA: dynamically created on the fly
Identified by a 16-bit SAID Connections are mapped to SAs Oct 22, 2008
23
IEEE 802.16 MAC – PS
--
Multi-level Keys and Their Usage
Public Key Contained in X.509 digital certificate Issued by SS manufacturers Used to encrypt AK
Authorization Key (AK) Provided by BS to SS at authorization Used to derive KEK Key Encryption Key (KEK) Derived from AK Used to encrypt TEK Traffic Encryption Key (TEK) Provided by BS to SS at key exchange Used to encrypt traffic data payload Oct 22, 2008
24
IEEE 802.16 MAC – PS -- Data Encryption
Use DES (Data Encryption Standard) in CBC (Cipher Block Chaining) mode with IV (Initialization Vector). CBC IV is calculated from IV parameter in TEK keying info; and PHY synchronization field in DLMAP. Only MAC PDU payload (including sub-headers) is encrypted. MAC PDU headers are unencrypted. Management messages are unencrypted. Oct 22, 2008
25
References
IEEE802.16-2004 Alcatel White Paper: WiMAX, making ubiquitous high-speed data services a reality Intel White Paper: Understanding WiMAX and 3G for Portable/Mobile Broadband Wireless WiMAX Forum: www.wimaxforum.com http://en.wikipedia.org/wiki/WiMax
Oct 22, 2008
26
IEEE 802.16 MAC – commonly used terms
BS – Base Station SS – Subscriber Station, (i.e., CPE) DL – Downlink, i.e. from BS to SS UL – Uplink, i.e. from SS to BS FDD – Frequency Division Duplex TDD – Time Division Duplex TDMA – Time Division Multiple Access TDM – Time Division Multiplexing OFDM – Orthogonal Frequency Division Multiplexing OFDMA - Orthogonal Frequency Division Multiple Access QoS – Quality of Service Oct 22, 2008
27
Application There are two main applications of Wi-MAX • fixed Wi-MAX applications are point-tomultipoint enabling broadband access to homes and businesses • Mobile Wi-MAX offers the full mobility of cellular networks at true broadband speeds. Both fixed and mobile applications of WiMAXare engineered to help deliver ubiquitous, high-throughput broadband wireless services at a low cost. . Oct 22, 2008
28
Application Mobile Wi-MAX is based on OFDMA (Orthogonal Frequency Division Multiple Access) technology which has inherent advantages in throughput, latency, spectral efficiency, and advanced antennae support; ultimately enabling it to provide higher performance than today's wide area wireless technologies. Furthermore, many next generation 4G wireless technologies may evolve towards OFDMA and all IP-based networks as an ideal for delivering cost-effective wireless data services Oct 22, 2008
29
Advantages Wi-MAX can effectively be used for point-to-point backhaul over long distances (up to 30 Miles). Unobstructed, Wi-MAX can span many miles and cover wide areas (up to 30 Miles). 4-6 Miles in non line-of-site applications vs. 150-300 ft for Wi-Fi. This makes it suitable for entire cities and allows development of Metropolitan Area Networks (MANs) versus Local Area Networks for Wi-Fi.
Oct 22, 2008
30
Advantages Wi-MAX promises to be internationally standardized, facilitating large production runs by multiple suppliers, bringing down equipment pricing. Wi-MAX has a higher speed than Wi-Fi and, depending on bandwidth availability, may produce data transmissions of up to 70 Mbps vs. 54 for Wi-Fi.
Oct 22, 2008
31
Advantages Wi-MAX can be used in both Line-of-Sight (LOS), for back-haul applications (up to 30 miles under ideal conditions), and non-LOS network access applications. Wi-MAX can be used to connect multiple network hot spots, and provide last-mile connectivity directly to the home or business. Wi-MAXcan use licensed or unlicensed spectrum.
Oct 22, 2008
32
Advantages Wi-MAX is symmetrical in most cases providing the same throughput upstream and downstream Since Wi-MAX does not use the Medium Voltage power lines for transport, the Radio Frequency Interference caused by signal transport over the Medium Voltage system.
Oct 22, 2008
33
WiMax Management Information Base (MIB).
Oct 22, 2008
34
WiMAX Mission Statement
The purpose of WiMAX is to promote deployment of broadband wireless access networks by using a global standard and certifying interoperability of products and technologies
Writing test specs Qualifying test labs Certifying products WiMAX is the next revolutionary technology after WiFi
Focus on interoperability Oct 22, 2008
36
IEEE 802.16a/d/e IEEE 802.16a – A Fixed Wireless Access standard
PtMP, connection oriented MAC layer Three Physical layers: OFDM, OFDMA and Single Carrier Approved in April 2003 IEEE 802.16d – now called IEEE 802.16-2004
Approved in July 2004 Focused on fixed applications Consolidates all amendments and base standard for WiMAX IEEE 802.16e – A Mobile Wireless Access standard
Incorporate features and protocols needed for portability/mobility
•
Modes added to enhance portability/mobility performance
HIPERMAN – the parallel H105 ETSI effort Expect final approval • Identical to 802.16a and 802.16d, except: • Only OFDM PHY
Oct 22, 2008
37
WiMAX Vision: Broadband Everywhere
1
3
2 FRACTIONAL BACKHAUL for T1 for SMALL BUSINESS HOTSPOTS
T1+ LEVEL SERVICE ENTERPRISE
Mobile Backhaul
RESIDENTIAL & SoHo DSL LEVEL SERVICE
802.1 6d
802.16 d
WMAN Nomadic Coverage --> handoff fromH HOT H SPOTS H H
802.1 6e
5
4
H
H H
H H = wide area coverage outside of Hot Spots
INTERNET BACKBONE BWA Operator Network Backbone Oct 22, 2008
Mobility 38
Salient features of BSNL WIMAX
WIMAX IN 10 CITIES-
KOLKATA, CHENNA, HYDERABAD, BANGLORE AHMEDABAD, PUNE, HISSAR, ROHTA, PINJORE and KARNAL 150 TYPE 1 CPEs.(3 RJ 45) VENDOR-MOTOROLA, APERTO TECNOLOGY FREQ. ALLOTTED- 2 FDD SPOTS OF 3.5 MHz. FOUR SECTORS 7.5MBPS*4 = 30 MBPS TOTAL NET THROUGHPUT BS CAPACITY-1000CPE,50 SUBSCRIBER/CPE MODEL-PM 5000 BS,PM 300i CPE. BS IS WIMAX CERTIFIED
Oct 22, 2008
39
WIMAX BS
Oct 22, 2008
40
WIMAX CPE components
Oct 22, 2008
41
Management Traffic connected to PE router via 128kbps MLLN circuit & data traffic to Tier-II
NMS Bangalore
1.
User Data is backhauled to the Tier II switch using Ethernet over SDH or relevant media.
2.
Management Data is transported to the PE router using a 128kbps MLLN backhaul.
3.
EMS Client connected to the PE using 128kbps MLLN backhaul
4.
All Management elements are part of a VPN.
EMS Server
City A BTS Location
Provider Router
MPLS CORE Tier I
Provider Router
Tier II
Broadband RAS/ Provider Edge
CPE Locations
Eth over SDH
Tier I
Eth over SDH
User/ Backhaul Data
Tier II EMS Client
Provider Edge Router 128Kbps Managed Leased Line Network
Management Data
Oct 22, 2008
42
Snapshot of Frequency Spectrum for WiMAX (2.3 - 5.8 GHz)
MMDS ~2500-2690 2700-2900
3.5GHz band 3400-3600 3300-3400
Low/Mid UNII-band (802.11a)
US WCS 2305-2320 2345-2360
~5725-5850
5150-5350
ISM (11b/g) 2400-2480
Upper UNII-band
WiMAX profiles available
WRC (new) 5470-5725
Other Bands
Note : WPC has allotted two no of FDD frequencies of 3.5 MHz (1) 3308.75 / 3358.75 MHz (2) 3312.25 / 3362.25 MHz Oct 22, 2008
43
Performance Requirement from WiMax
CPE Performance: 8 Mbps net throughput per sector Shall support 50 subscriber per CPE BSNL has specifically asked for V5.2, G703,Gx interface in BS & POTS, VOIP, USB,G703 interfaces in CPE besides the normal FE interface in BS & CPE. BSNL has given 1 Year time frame to bidder to provide these interfaces since these are not available with any bidders.
Oct 22, 2008
44
APPLICATIONS OF WIMAX
Multiple broadband from a single CPE.(Each subs. With different SLA) Backhaul of wi-fi Backhaul of DSLMP Internet lease line. MPLS VPN sopport.
Oct 22, 2008
45
DSLAM BACKHAUL APPLICATION Up to 20kmts Ethernet
Ethernet CANOPY
CANOPY
CANOPY
Wi-Max BTS DSLAM
Wi-Max CPE
DSLAM Wi-Max CPE Location-2
Location-1 Ethernet Switch
BRAS
Oct 22, 2008
INTERNET BACKBONE 46
Wireless Broadband Application
FIG-2
SME
ENTERPRISE
Wi-Max CPE
Wi-Max CPE
KIOSK CANOPY
CANOPY
CANOPY
Wi-Max Base Station Wi-Fi Access Point
Wi-Max CPE
Wi-Max CPE
Wi-Fi HOTSPOT
INTERNET BACKBONE
Oct 22, 2008
47
BROADBAND SERVICE USING WI-MAX Ethernet Cable Wi-Max CPE Ethernet Switch
Wi-Max Base Station C A NO P Y
C A NO P Y
CANOPY
INTERNET BACKBONE
Oct 22, 2008
48
BROADBAND SERVICE USING WI-FI AND WI-MAX
Wi-Max CPE
Wi-Fi Access Point
Wi-Max Base Station C A NO P Y
C A NO P Y
CANOPY
INTERNET BACKBONE
Oct 22, 2008
49
FIG-5 MPLS-VPN CONNECTIVITY SME
ENTERPRISE
Wi-Max CPE
Wi-Max CPE
SME CANOPY
CANOPY
CANOPY
Wi-Max Base Station SWITCH
MPLS NETWORK
Oct 22, 2008
Wi-Max CPE
INTERNET BACKBONE
50
Combined VoIP, DSL & Wi-Max Solution for URBAN and RURAL Telephony
CO
Local PSTN Cu Pairs
Media Gateway SIP Proxy & Media Server
1 BSNL INTERNET IP
POTS Splitter
10/100B T
Existing Loop Network Voice & Data
SOHO DSL CPE ATA
IP DSLAM BRAS
Aperto Wi-Max Network
Rural Telephony Aperto Wireless Access
2
Oct 22, 2008
2
Wi-Max CPE 1
1
3 Analog 24 port FXS gateway
2 4
51
Issues with WI-MAX Equipment 4. Site survey 5. 5.2/G703 interfaces at CPE & BS end. 6. Height of Antenna at CPE end for longer distance. 7. Upgradation/Replacement to certified equipment.
Oct 22, 2008
52
Issues Issues with Wi-MAX
Upstream Bit Rate, Downstream Bit Rate, Acceptable Outage Time, Security, and Encryption, Video Quality, Internet Speeds, Streaming Video, Bandwidth & Efficiency, Voice over IP, Gaming Encryption, Appropriate Frequency Tolerance to Interference and Gateway Priority - Video Data
Oct 22, 2008
53
THANK YOU
Related Documents
Dcs Wi Max Protocol
November 2019 4
Dcs Overview On Wi Max
November 2019 5
Wi-max
June 2020 6
Wi-max
June 2020 3
Wi Max
August 2019 10