The document discusses dynamic quality of service (QoS) management in IEEE 802.16 wireless networks. It describes four service classes defined by the 802.16 MAC layer: Unsolicited Grant Service (UGS), Real-time Polling Service (rtPS), Non-real-time Polling Service (nrtPS), and Best Effort (BE) service. It also discusses how the 802.16 standard uses mechanisms like dynamic adjustment of downlink and uplink burst profiles to manage QoS and bandwidth.
Performance analysis of Multiband - OFDM systems using LDPC coder in pulsed -...IDES Editor
In this paper, a combined approach where low density
parity check (LDPC) codes are used to reduce the complexity
and power consumption of pulsed orthogonal frequencydivision
multiplexing (pulsed-OFDM) ultra-wideband (UWB)
systems is described. The proposed system uses LDPC codes
to achieve higher code rates without using convolution
encoding and puncturing thereby reducing the complexity and
power consumption of pulsed-OFDM system. The LDPCpulsed-
OFDM system achieves channel capacity with different
code rates and has good performance in different channel
fading scenarios. The pulsed OFDM system is used where
pulsed signals could spread the frequency spectrum of the
OFDM signal. The performance of LDPC-pulsed-OFDM
system for wireless personal area networks (WPAN) is
analyzed for different UWB indoor propagation channels (CM3
and CM4) provided by the IEEE 802.15.3a Standard activity
committee. To establish this, a design of LDPC-pulsed-OFDM
system using the digital video broadcasting-satellite-second
generation (DVB-S2) standard and provide the simulation
results for the different code rates supported by LDPC codes
is presented.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document discusses various types of call forwarding in 3 sentences:
It describes unconditional and conditional call forwarding scenarios as well as no reply, busy, and not reachable scenarios. The state transition models show the signaling flows between network elements like the GMSC, HLR, MSC, and VLR when a call is forwarded due to various conditions like absent subscriber, no reply, radio congestion, or detachment. Registration, erasure, activation, and deactivation functions are also covered with regard to managing call forwarding numbers and services.
The document discusses the topics covered in modules about Global System for Mobile Communications (GSM). It provides an overview of GSM architecture and components like the mobile station, base station subsystem, network switching subsystem and their interfaces. It describes the different generations of cellular networks and GSM channels. It also covers concepts like cell planning, hardware for different network nodes, call paths for various call types, data services, mobile packet backbone network and the evolution of GSM.
This document provides an overview of CDMA (Code Division Multiple Access), including its access schemes, coding, codes, spreading process, power control, handover, multipath and rake receivers. It describes how CDMA uses unique spreading codes to spread data before transmission. Receivers use correlators to despread the signal and filters to isolate the desired signal from interference. Power control is important to limit interference in this interference-limited system. Soft handovers allow connections between multiple cells. Multipath signals are combined using rake receivers to strengthen the signal.
1) The document describes the physical layer signals and channels of 3GPP LTE, including synchronization signals, reference signals, control channels, and shared channels.
2) Key signals include primary and secondary synchronization signals for cell identification, and reference signals for channel estimation. Control channels include the physical downlink control channel for scheduling and the physical uplink control channel.
3) Shared channels are used to carry user data and control information. The physical downlink shared channel conveys downlink payloads while the physical uplink shared channel carries uplink payloads. Modulation schemes include QPSK, 16QAM, and 64QAM.
This document outlines the topics that will be covered in a GSM training course for professionals. The course covers 10 modules on topics related to GSM architecture, channel concepts, cell planning, hardware, call paths, data services, evolution to LTE, and more. Each module will provide an in-depth look at key aspects of GSM networks to help professionals gain expertise in this area.
The document describes the air interface structure in GSM networks. It discusses the structure of bursts, logical channels, and how logical channels are mapped to physical channels. The key points are:
1) Bursts contain formatted bits of information or control data sent during a time slot. The main burst types are normal, access, and synchronization bursts.
2) Logical channels transport specific information types like traffic, broadcast control, or paging data. Common logical channels include BCCH, PCH, RACH, SDCCH, and TCH.
3) Logical channels are multiplexed and transmitted on physical channels defined by a carrier frequency and time slot. Mapping rules determine which physical channels carry each logical
Performance analysis of Multiband - OFDM systems using LDPC coder in pulsed -...IDES Editor
In this paper, a combined approach where low density
parity check (LDPC) codes are used to reduce the complexity
and power consumption of pulsed orthogonal frequencydivision
multiplexing (pulsed-OFDM) ultra-wideband (UWB)
systems is described. The proposed system uses LDPC codes
to achieve higher code rates without using convolution
encoding and puncturing thereby reducing the complexity and
power consumption of pulsed-OFDM system. The LDPCpulsed-
OFDM system achieves channel capacity with different
code rates and has good performance in different channel
fading scenarios. The pulsed OFDM system is used where
pulsed signals could spread the frequency spectrum of the
OFDM signal. The performance of LDPC-pulsed-OFDM
system for wireless personal area networks (WPAN) is
analyzed for different UWB indoor propagation channels (CM3
and CM4) provided by the IEEE 802.15.3a Standard activity
committee. To establish this, a design of LDPC-pulsed-OFDM
system using the digital video broadcasting-satellite-second
generation (DVB-S2) standard and provide the simulation
results for the different code rates supported by LDPC codes
is presented.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document discusses various types of call forwarding in 3 sentences:
It describes unconditional and conditional call forwarding scenarios as well as no reply, busy, and not reachable scenarios. The state transition models show the signaling flows between network elements like the GMSC, HLR, MSC, and VLR when a call is forwarded due to various conditions like absent subscriber, no reply, radio congestion, or detachment. Registration, erasure, activation, and deactivation functions are also covered with regard to managing call forwarding numbers and services.
The document discusses the topics covered in modules about Global System for Mobile Communications (GSM). It provides an overview of GSM architecture and components like the mobile station, base station subsystem, network switching subsystem and their interfaces. It describes the different generations of cellular networks and GSM channels. It also covers concepts like cell planning, hardware for different network nodes, call paths for various call types, data services, mobile packet backbone network and the evolution of GSM.
This document provides an overview of CDMA (Code Division Multiple Access), including its access schemes, coding, codes, spreading process, power control, handover, multipath and rake receivers. It describes how CDMA uses unique spreading codes to spread data before transmission. Receivers use correlators to despread the signal and filters to isolate the desired signal from interference. Power control is important to limit interference in this interference-limited system. Soft handovers allow connections between multiple cells. Multipath signals are combined using rake receivers to strengthen the signal.
1) The document describes the physical layer signals and channels of 3GPP LTE, including synchronization signals, reference signals, control channels, and shared channels.
2) Key signals include primary and secondary synchronization signals for cell identification, and reference signals for channel estimation. Control channels include the physical downlink control channel for scheduling and the physical uplink control channel.
3) Shared channels are used to carry user data and control information. The physical downlink shared channel conveys downlink payloads while the physical uplink shared channel carries uplink payloads. Modulation schemes include QPSK, 16QAM, and 64QAM.
This document outlines the topics that will be covered in a GSM training course for professionals. The course covers 10 modules on topics related to GSM architecture, channel concepts, cell planning, hardware, call paths, data services, evolution to LTE, and more. Each module will provide an in-depth look at key aspects of GSM networks to help professionals gain expertise in this area.
The document describes the air interface structure in GSM networks. It discusses the structure of bursts, logical channels, and how logical channels are mapped to physical channels. The key points are:
1) Bursts contain formatted bits of information or control data sent during a time slot. The main burst types are normal, access, and synchronization bursts.
2) Logical channels transport specific information types like traffic, broadcast control, or paging data. Common logical channels include BCCH, PCH, RACH, SDCCH, and TCH.
3) Logical channels are multiplexed and transmitted on physical channels defined by a carrier frequency and time slot. Mapping rules determine which physical channels carry each logical
This document summarizes a research paper on a CDMA-based MAC protocol for wireless ad hoc networks. The protocol, called CA-CDMA, addresses the near-far problem in CDMA systems by incorporating distributed power control and interference feedback between nodes. Simulation results show that CA-CDMA can increase throughput by up to 280% compared to 802.11 by allowing simultaneous transmissions through power control. Future work may involve combining CA-CDMA with other capacity enhancement techniques like directional antennas or multi-rate support.
Spread spectrum techniques spread data signals over a wide bandwidth to make them resistant to jamming and interception. There are two main approaches: frequency hopping spread spectrum (FHSS) rapidly switches a narrowband signal across a wide band of frequencies in a pattern known only to the transmitter and receiver, while direct sequence spread spectrum (DSSS) encodes data bits by adding extra bits using a spreading code before transmission. Code division multiple access (CDMA) allows multiple users to share the same frequency band by using user-specific spreading codes, with the signals combined at the receiver.
There are four main types of spread spectrum techniques: direct sequence spread spectrum (DSSS), frequency hopping spread spectrum (FHSS), time hopping spread spectrum (THSS), and hybrid techniques. DSSS uses a pseudo-noise code to spread the bandwidth of digital data. FHSS discretely shifts the carrier frequency in a pattern determined by a code sequence. THSS varies the period and duty cycle of a pulsed RF carrier in a pseudo-random manner. Hybrid techniques combine methods, such as DSSS and FHSS, to leverage advantages from multiple techniques.
The document discusses CDMA and 3G spread spectrum technology. It describes how CDMA uses direct sequence spread spectrum to allow multiple users to access the same frequency band simultaneously. It explains the key elements of spread spectrum communication including using a chip rate that is faster than the data rate, synchronization at the receiver, and using pseudo-random codes. It provides details on IS-95 CDMA including channel structures, call processing, and authentication.
WCDMA uses spread spectrum technology to allow multiple users to access the same frequency band simultaneously. It spreads user data over a wide bandwidth through multiplication with unique spreading codes. At the receiver, the desired user's signal is recovered through correlation with the same spreading code. WCDMA employs RAKE receivers to combine signals from different propagation paths using maximal ratio combining for improved reception. Power control is used to manage interference between users communicating over the same frequency channel.
The document discusses various aspects of GSM including:
1. The functions of SDCCH and SACCH channels which include location updates, SMS, ciphering initiation, and more.
2. Reasons for handovers including signal strength, quality, power budget, and interference. Shortcomings like call dropping, ping-pong effects, and far-away cell effects are also discussed.
3. Intelligent handover techniques like fuzzy logic and neural networks. Internal handovers between channels in the same cell and external handovers between different BTS, BSC, and MSC are defined.
4. Frequency hopping helps with frequency diversity, interference averaging, and network capacity by enabling more aggressive
This document describes a fully programmable frequency divider and dual-modulus prescaler for high-speed frequency operation between 1.8 GHz and 2.4 GHz in a phase locked loop (PLL) system using 250nm CMOS technology. It presents the architecture of a programmable frequency divider consisting of a dual-modulus prescaler, programmable counter, and swallow counter. A high-speed dynamic D flip-flop is used to reduce power consumption. The paper also describes the operation of a divide-by-2 frequency divider circuit using a true single-phase clock logic topology and explains how this can be extended to a divide-by-2/3 prescaler. The maximum operating frequency is 2.
LTE TDD uses time division duplexing to separate uplink and downlink transmissions on the same frequency band. It divides each 10ms frame into uplink and downlink timeslots. Key aspects of LTE TDD include its frame structure with special subframes containing DwPTS, GP and UpPTS fields, supported frequency bands and bandwidths, and physical channels such as PDSCH, PDCCH, and PRACH that operate differently than in LTE FDD. Network planning requires consideration of uplink/downlink configuration and propagation delays between base stations and mobile stations.
3GPP is a collaboration between standards bodies to develop 3G wireless technology standards. It has released several versions (releases) of the standards over time, each building upon the previous release and adding new functionality. The major releases include Release 99 which defined basic 3G functionality, Release 4 which added features like QoS optimization, and Release 5 which focused on multimedia services and technologies like HSDPA. Later releases such as Release 6 added features like MBMS and IMS enhancements. 3GPP continues to evolve the standards with each new release.
This document provides an overview of spread spectrum technologies including frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS). It defines spread spectrum, describes how data is modulated at different rates using DSSS, explains FHSS and DSSS in detail, and lists factors that impact wireless signal performance. Key aspects covered include the FCC regulations for unlicensed use of spread spectrum in the 2.4GHz band, how DSSS spreads and encodes data across multiple frequencies, and how FHSS rapidly hops between frequencies to transmit information.
This document provides summaries of key concepts in GSM RF including:
1) GSM PLMN services including bearer, tele, and supplementary services.
2) GSM 900 and DCS 1800 uplink and downlink frequency ranges.
3) Ciphering and authentication processes to encode transmissions and verify identities.
4) Equalization, interleaving, and other techniques used to extract signals and spread data across timeframes.
This document provides an analysis of different pseudorandom and orthogonal spreading sequences used in direct sequence code division multiple access (DS-CDMA). It begins with an introduction to CDMA transmission and reception and an example of direct sequence spread spectrum. It then discusses various pseudorandom sequences like maximal length sequences, Gold sequences, Gold-like sequences, Barker sequences, and Kasami sequences. It also covers orthogonal sequences including Walsh-Hadamard codes, modified Walsh-Hadamard codes, and orthogonal variable spreading factor codes. The document concludes by comparing the performance of these different sequences based on their correlation properties and suitability for use in CDMA networks.
Exact Outage Performance Analysis of Amplify-and-forward-aware Cooperative NOMATELKOMNIKA JOURNAL
In this paper, new radio access scheme that combines Amplify-and-Forward (AF) relaying protocol and non-orthogonal multiple access (NOMA) system is introduced. In particular, different scenarios for fixed power allocation scheme is investigated. In addition, the outage probability of both weak and strong user is derived and provided in closed-form expressions. Such outage is investigated in high SNR scenario and comparison performance between these NOMA scenarios is introduced. Numerical simulations are offered to clarify the outage performance of the considered scheme if varying several parameters in the existing schemes to verify the derived formulas.
Qpsk modulation for dsss cdma transmitter and receiver using fpgaIAEME Publication
This document describes a QPSK modulation and demodulation system for a DS-CDMA transmitter and receiver implemented on an FPGA. It discusses:
1) The DS-CDMA transmitter which consists of a user data generator, PN sequence generator for spreading, and QPSK modulator to modulate the spread signal before transmission.
2) The DS-CDMA receiver which consists of a QPSK demodulator, PN sequence generator for despreading, matched filter, and threshold detector to recover the transmitted data.
3) The implementation of QPSK modulation and demodulation, where 2 bits are mapped to signal phases and modulation is performed by varying the phase of a carrier signal.
This document discusses enhancements to the physical layer of LTE-Advanced (3GPP Release 10). It describes the downlink and uplink physical layer designs, including orthogonal multiple access schemes, reference signals, control signaling, and data transmission methods. It also covers support for time division duplexing, half-duplex frequency division duplexing, and UE categories defined in 3GPP Release 8. The goal of LTE-Advanced is to further improve the LTE standard to meet the requirements of IMT-Advanced.
This document provides an overview of UMTS basic theory. It covers radio basics, UMTS spectrum planning, and principles of spread spectrum communication. It discusses TDD and FDD duplex modes, multiple access technologies including FDMA, TDMA, and CDMA. It also covers UMTS spectrum allocation, channel encoding, interleaving, and the basics of direct sequence spread spectrum communication used in UMTS.
The document discusses handoff in cellular networks. It begins by explaining that handoff is required when a mobile moves between coverage areas of different cells during a call. The main points are:
1) The MSC must identify a new BS to handle the call and seamlessly transfer control to it, assigning the call new forward and reverse channels.
2) Important performance metrics for handoff include it being seamless to the user, minimizing unnecessary handoffs, low probability of blocking new calls in the new cell, and handing off to a channel with good signal quality.
3) Handoff involves initiation when a need is identified, reserving resources in the new cell, executing the actual handoff, and free
The document discusses several aspects of wireless personal area networks (WPANs), focusing on Bluetooth and ZigBee technologies. It defines WPANs as conveying information over short distances with little infrastructure. Bluetooth is described as the most widely used WPAN technology, operating using piconets of up to 8 devices within 10 meters of each other. Key aspects of Bluetooth like frequency hopping, link types, and data rates are summarized. The Bluetooth architecture is broken down into its radio, baseband, link manager, and L2CAP layers.
The document describes IEEE 802.16j multi-hop relay networks. It outlines the benefits of using relay stations such as coverage extension and throughput enhancement. It discusses key concepts like relay links and access links. The document also provides details on relay station network entry procedures including scanning, synchronization, ranging, registration. It explains relay frame structure and functional blocks. Finally, it summarizes procedures like neighbor measurement reporting, access station selection, and operation parameter configuration.
IEEE 802.16 is a standard for wireless metropolitan area networks (WirelessMANs) that provides broadband wireless access over several kilometers. It uses point-to-multipoint architecture with base stations and subscriber stations. WiMAX is a wireless technology that conforms to the IEEE 802.16 standard and aims to provide "last mile" wireless broadband access. The standard defines the physical and media access control layers for both fixed and mobile broadband wireless access.
The document discusses GSM signaling and mobile signaling. GSM signaling defines communications between the mobile and network using different protocols across interfaces. Mobile signaling involves the mobile searching for frequencies, synchronizing, downloading information, selecting a network, and signaling to the network by sending a service request when a call is made.
This document summarizes a research paper on a CDMA-based MAC protocol for wireless ad hoc networks. The protocol, called CA-CDMA, addresses the near-far problem in CDMA systems by incorporating distributed power control and interference feedback between nodes. Simulation results show that CA-CDMA can increase throughput by up to 280% compared to 802.11 by allowing simultaneous transmissions through power control. Future work may involve combining CA-CDMA with other capacity enhancement techniques like directional antennas or multi-rate support.
Spread spectrum techniques spread data signals over a wide bandwidth to make them resistant to jamming and interception. There are two main approaches: frequency hopping spread spectrum (FHSS) rapidly switches a narrowband signal across a wide band of frequencies in a pattern known only to the transmitter and receiver, while direct sequence spread spectrum (DSSS) encodes data bits by adding extra bits using a spreading code before transmission. Code division multiple access (CDMA) allows multiple users to share the same frequency band by using user-specific spreading codes, with the signals combined at the receiver.
There are four main types of spread spectrum techniques: direct sequence spread spectrum (DSSS), frequency hopping spread spectrum (FHSS), time hopping spread spectrum (THSS), and hybrid techniques. DSSS uses a pseudo-noise code to spread the bandwidth of digital data. FHSS discretely shifts the carrier frequency in a pattern determined by a code sequence. THSS varies the period and duty cycle of a pulsed RF carrier in a pseudo-random manner. Hybrid techniques combine methods, such as DSSS and FHSS, to leverage advantages from multiple techniques.
The document discusses CDMA and 3G spread spectrum technology. It describes how CDMA uses direct sequence spread spectrum to allow multiple users to access the same frequency band simultaneously. It explains the key elements of spread spectrum communication including using a chip rate that is faster than the data rate, synchronization at the receiver, and using pseudo-random codes. It provides details on IS-95 CDMA including channel structures, call processing, and authentication.
WCDMA uses spread spectrum technology to allow multiple users to access the same frequency band simultaneously. It spreads user data over a wide bandwidth through multiplication with unique spreading codes. At the receiver, the desired user's signal is recovered through correlation with the same spreading code. WCDMA employs RAKE receivers to combine signals from different propagation paths using maximal ratio combining for improved reception. Power control is used to manage interference between users communicating over the same frequency channel.
The document discusses various aspects of GSM including:
1. The functions of SDCCH and SACCH channels which include location updates, SMS, ciphering initiation, and more.
2. Reasons for handovers including signal strength, quality, power budget, and interference. Shortcomings like call dropping, ping-pong effects, and far-away cell effects are also discussed.
3. Intelligent handover techniques like fuzzy logic and neural networks. Internal handovers between channels in the same cell and external handovers between different BTS, BSC, and MSC are defined.
4. Frequency hopping helps with frequency diversity, interference averaging, and network capacity by enabling more aggressive
This document describes a fully programmable frequency divider and dual-modulus prescaler for high-speed frequency operation between 1.8 GHz and 2.4 GHz in a phase locked loop (PLL) system using 250nm CMOS technology. It presents the architecture of a programmable frequency divider consisting of a dual-modulus prescaler, programmable counter, and swallow counter. A high-speed dynamic D flip-flop is used to reduce power consumption. The paper also describes the operation of a divide-by-2 frequency divider circuit using a true single-phase clock logic topology and explains how this can be extended to a divide-by-2/3 prescaler. The maximum operating frequency is 2.
LTE TDD uses time division duplexing to separate uplink and downlink transmissions on the same frequency band. It divides each 10ms frame into uplink and downlink timeslots. Key aspects of LTE TDD include its frame structure with special subframes containing DwPTS, GP and UpPTS fields, supported frequency bands and bandwidths, and physical channels such as PDSCH, PDCCH, and PRACH that operate differently than in LTE FDD. Network planning requires consideration of uplink/downlink configuration and propagation delays between base stations and mobile stations.
3GPP is a collaboration between standards bodies to develop 3G wireless technology standards. It has released several versions (releases) of the standards over time, each building upon the previous release and adding new functionality. The major releases include Release 99 which defined basic 3G functionality, Release 4 which added features like QoS optimization, and Release 5 which focused on multimedia services and technologies like HSDPA. Later releases such as Release 6 added features like MBMS and IMS enhancements. 3GPP continues to evolve the standards with each new release.
This document provides an overview of spread spectrum technologies including frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS). It defines spread spectrum, describes how data is modulated at different rates using DSSS, explains FHSS and DSSS in detail, and lists factors that impact wireless signal performance. Key aspects covered include the FCC regulations for unlicensed use of spread spectrum in the 2.4GHz band, how DSSS spreads and encodes data across multiple frequencies, and how FHSS rapidly hops between frequencies to transmit information.
This document provides summaries of key concepts in GSM RF including:
1) GSM PLMN services including bearer, tele, and supplementary services.
2) GSM 900 and DCS 1800 uplink and downlink frequency ranges.
3) Ciphering and authentication processes to encode transmissions and verify identities.
4) Equalization, interleaving, and other techniques used to extract signals and spread data across timeframes.
This document provides an analysis of different pseudorandom and orthogonal spreading sequences used in direct sequence code division multiple access (DS-CDMA). It begins with an introduction to CDMA transmission and reception and an example of direct sequence spread spectrum. It then discusses various pseudorandom sequences like maximal length sequences, Gold sequences, Gold-like sequences, Barker sequences, and Kasami sequences. It also covers orthogonal sequences including Walsh-Hadamard codes, modified Walsh-Hadamard codes, and orthogonal variable spreading factor codes. The document concludes by comparing the performance of these different sequences based on their correlation properties and suitability for use in CDMA networks.
Exact Outage Performance Analysis of Amplify-and-forward-aware Cooperative NOMATELKOMNIKA JOURNAL
In this paper, new radio access scheme that combines Amplify-and-Forward (AF) relaying protocol and non-orthogonal multiple access (NOMA) system is introduced. In particular, different scenarios for fixed power allocation scheme is investigated. In addition, the outage probability of both weak and strong user is derived and provided in closed-form expressions. Such outage is investigated in high SNR scenario and comparison performance between these NOMA scenarios is introduced. Numerical simulations are offered to clarify the outage performance of the considered scheme if varying several parameters in the existing schemes to verify the derived formulas.
Qpsk modulation for dsss cdma transmitter and receiver using fpgaIAEME Publication
This document describes a QPSK modulation and demodulation system for a DS-CDMA transmitter and receiver implemented on an FPGA. It discusses:
1) The DS-CDMA transmitter which consists of a user data generator, PN sequence generator for spreading, and QPSK modulator to modulate the spread signal before transmission.
2) The DS-CDMA receiver which consists of a QPSK demodulator, PN sequence generator for despreading, matched filter, and threshold detector to recover the transmitted data.
3) The implementation of QPSK modulation and demodulation, where 2 bits are mapped to signal phases and modulation is performed by varying the phase of a carrier signal.
This document discusses enhancements to the physical layer of LTE-Advanced (3GPP Release 10). It describes the downlink and uplink physical layer designs, including orthogonal multiple access schemes, reference signals, control signaling, and data transmission methods. It also covers support for time division duplexing, half-duplex frequency division duplexing, and UE categories defined in 3GPP Release 8. The goal of LTE-Advanced is to further improve the LTE standard to meet the requirements of IMT-Advanced.
This document provides an overview of UMTS basic theory. It covers radio basics, UMTS spectrum planning, and principles of spread spectrum communication. It discusses TDD and FDD duplex modes, multiple access technologies including FDMA, TDMA, and CDMA. It also covers UMTS spectrum allocation, channel encoding, interleaving, and the basics of direct sequence spread spectrum communication used in UMTS.
The document discusses handoff in cellular networks. It begins by explaining that handoff is required when a mobile moves between coverage areas of different cells during a call. The main points are:
1) The MSC must identify a new BS to handle the call and seamlessly transfer control to it, assigning the call new forward and reverse channels.
2) Important performance metrics for handoff include it being seamless to the user, minimizing unnecessary handoffs, low probability of blocking new calls in the new cell, and handing off to a channel with good signal quality.
3) Handoff involves initiation when a need is identified, reserving resources in the new cell, executing the actual handoff, and free
The document discusses several aspects of wireless personal area networks (WPANs), focusing on Bluetooth and ZigBee technologies. It defines WPANs as conveying information over short distances with little infrastructure. Bluetooth is described as the most widely used WPAN technology, operating using piconets of up to 8 devices within 10 meters of each other. Key aspects of Bluetooth like frequency hopping, link types, and data rates are summarized. The Bluetooth architecture is broken down into its radio, baseband, link manager, and L2CAP layers.
The document describes IEEE 802.16j multi-hop relay networks. It outlines the benefits of using relay stations such as coverage extension and throughput enhancement. It discusses key concepts like relay links and access links. The document also provides details on relay station network entry procedures including scanning, synchronization, ranging, registration. It explains relay frame structure and functional blocks. Finally, it summarizes procedures like neighbor measurement reporting, access station selection, and operation parameter configuration.
IEEE 802.16 is a standard for wireless metropolitan area networks (WirelessMANs) that provides broadband wireless access over several kilometers. It uses point-to-multipoint architecture with base stations and subscriber stations. WiMAX is a wireless technology that conforms to the IEEE 802.16 standard and aims to provide "last mile" wireless broadband access. The standard defines the physical and media access control layers for both fixed and mobile broadband wireless access.
The document discusses GSM signaling and mobile signaling. GSM signaling defines communications between the mobile and network using different protocols across interfaces. Mobile signaling involves the mobile searching for frequencies, synchronizing, downloading information, selecting a network, and signaling to the network by sending a service request when a call is made.
WiFiRe is a system that extends the range of WiFi signals to 15-20 km using sectorized directional antennas to provide broadband wireless access to rural villages in India. It uses a single WiFi channel shared across all sectors, with a WiMAX-like MAC layer to coordinate multi-sector transmissions and guarantee quality of service for voice traffic. Key benefits are low cost using off-the-shelf WiFi components without requiring wireless spectrum licensing.
WiMAX (Worldwide Interoperability for Microwave Access) uses the IEEE 802.16 standards for broadband wireless access over long distances. It supports both point-to-multipoint and mesh topologies with a connection-oriented MAC layer that provides quality of service. The physical layer uses OFDM, OFDMA, or single carrier modulation and the MAC layer supports various services classes for different types of traffic.
WiMAX (IEEE 802.16) is a wireless broadband technology that provides transmission of data using a radio link instead of a cable infrastructure. It uses multiple access schemes such as OFDM and OFDMA to allow transmission to multiple users. The 802.16 standard defines the MAC layer which includes QoS, security, and bandwidth allocation to manage communication between the base station and subscriber stations.
The document discusses the key aspects of the IEEE 802.16 (WiMAX) standard for broadband wireless access. It describes the 802.16 MAC layer, including its reference model, convergence and common part sublayers, quality of service support, and security features. It also outlines the 802.16 PHY layer specifications and frame structures for different duplexing schemes.
The document describes a DVB-RCS satellite network for educational content delivery. It includes:
- A hub station that manages bandwidth allocation and network control for satellite interactive terminals (SITs).
- SITs that receive educational programs from a teaching end via satellite and allow two-way interaction through return links.
- A system using MF-TDMA to divide satellite bandwidth into time slots allocated to SITs to carry return traffic.
- Components of the SIT including the outdoor unit with antenna and indoor unit with an Ethernet interface.
This document discusses the physical layer design of LTE-Advanced. It describes the downlink and uplink physical layer designs, including support for time-division duplexing and half-duplex frequency-division duplexing. It also discusses UE categories defined in Release 8 and planned enhancements for LTE-Advanced. The physical layer specifications use OFDMA in the downlink and SC-FDMA in the uplink, with support for bandwidths up to 20 MHz.
This document discusses enhancements to the physical layer of LTE-Advanced (3GPP Release 10). It describes the downlink and uplink physical layer designs, including orthogonal multiple access schemes, reference signals, control signaling, and data transmission methods. It also covers support for time division duplexing, half-duplex frequency division duplexing, and UE categories defined in 3GPP Release 8. The goal of LTE-Advanced is to further improve the LTE standard to meet the requirements of IMT-Advanced.
Physical layer aspects (Matthew Baker: RAN WG1 Chair, Alcatel-Lucent) BP Tiwari
This document discusses the physical layer design of LTE-Advanced. It describes the downlink and uplink physical layer designs, including the use of OFDMA in the downlink and SC-FDMA in the uplink. It also discusses support for time division duplexing and half-duplex frequency division duplexing. Enhancements to user equipment categories and the physical layer for LTE-Advanced are also covered.
The document provides information on the evolution of wireless networks from 1G to 3G. It discusses the key components and architecture of cellular systems including base stations, mobile switching centers and their connection to the public switched telephone network. It also compares the differences between wireless and wired networks, and describes some of the limitations of early wireless networking. Finally, it covers topics like traffic routing, circuit switching, packet switching and the X.25 protocol.
This document provides an overview of two fundamental mechanisms in LTE access networks: random access and buffer status reporting. It describes the random access procedure used by UEs to connect to the network, including the exchange of preambles, responses, and temporary identifiers. It also explains the buffer status reporting procedure, where UEs indicate to the base station the amount of data waiting to be transmitted so that uplink resources can be allocated. Key parameters for both mechanisms are defined in 3GPP specifications to optimize performance and control signaling in the network.
This chapter discusses the Gb interface, which connects a packet control unit (PCU) and a serving GPRS support node (SGSN). It describes the layered structure of the Gb interface and the protocols used at each layer. The physical layer can use different technologies. Above this is the network service layer, which provides virtual circuits using protocols like Frame Relay. The base station subsystem GPRS protocol (BSSGP) manages buffers and virtual circuits. This layered design allows evolution of the underlying network without changing higher layers. The chapter then examines specific aspects of the protocols used, including Frame Relay frame structure and procedures, network service addressing, and protocol data unit formats.
MPLS is a forwarding scheme designed to speed up IP packet forwarding by using fixed length labels in packet headers to determine forwarding instead of long IP addresses. MPLS provides fast failure restoration through approaches like local protection which uses label stacking to allow a single bypass tunnel to protect multiple primary label switched paths (LSPs). Frame Relay is a public WAN technology based on packet switching that establishes virtual circuits between user ports to transport variable length data frames. It offers advantages over leased lines like more efficient use of bandwidth and topology flexibility but does not guarantee frame delivery. Asynchronous Transfer Mode (ATM) is a cell switching standard using small fixed size packets to efficiently multiplex different types of digital traffic like voice, data and images.
Frame Relay is a packet-switched WAN technology that transports variable-length frames over permanent virtual circuits (PVCs). It provides connection-oriented transmission of user data between two endpoints via a transparent logical link. Frame Relay operates at the data link layer and does not provide error or flow control, relying instead on higher layers for reliability. It offers bandwidth on demand and more efficient use of WAN links compared to traditional leased lines.
This document summarizes the physical layer design of LTE Release 8 and enhancements for LTE-Advanced. It describes the downlink and uplink multiple access schemes, reference signals, control signaling, data transmission procedures, UE categories, and support for frequency division duplex and time division duplex operation. The document provides an overview of the 3GPP release timeline and the specifications that define the LTE physical layer.
This document discusses definitions and common misuses of four telecommunications terms: bandwidth, bit rate, symbol, and baud. It begins by defining bandwidth from several perspectives, including the commonly used 3dB power rule definition. It then discusses how information transmission capacity is measured in bits per second, and how modulation techniques like QPSK and 8-PSK can pack more bits per hertz of bandwidth. While bits per second and bauds are synonymous in binary modulation, they differ in higher-order modulation. Overall, the document seeks to resolve ambiguities around these terms and advocate for more precise usage.
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.
1. WMAN, part 2
Contents
Part 1: IEEE 802.16 family of standards
Protocol layering
TDD frame structure
MAC PDU structure
Part 2: Dynamic QoS management
OFDM PHY layer
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 1
2. WMAN, part 2
Four service classes
The IEEE 802.16 MAC layer defines four service classes:
• Unsolicited Grant Service (UGS)
• Real-time Polling Service (rtPS)
QoS increases
QoS increases
• Non-real-time Polling Service (nrtPS)
• Best Effort (BE) service
The scheduling algorithms needed for implementing the
three first types of services are implemented in the BS
(while allocating uplink bandwidth to each SS) and are not
defined in the 802.16 standard. Each SS negotiates its
service policies with the BS at the connection setup time.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 2
3. WMAN, part 2
Unsolicited grant service (UGS)
UGS UGS offers fixed size grants on a real-time periodic
UGS
basis, which eliminates the overhead and latency of
rtPS
rtPS SS requests and assures that grants are available to
nrtPS
nrtPS meet the flow’s real-time needs. The BS provides
fixed size bursts in the uplink at periodic intervals for
BE
BE the service flow. The burst size and other parameters
are negotiated at connection setup.
Typical UGS applications: E1/T1 links (containing e.g.
delay-sensitive speech signals), VoIP (without silence
suppression).
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 3
4. WMAN, part 2
Real-time Polling Service (rtPS)
UGS The Real-time Polling Service (rtPS) is designed to
UGS
support real-time service flows that generate variable
rtPS
rtPS size data packets on a periodic basis, such as VoIP
nrtPS
nrtPS (with silence suppression) or streaming video.
BE
BE This service offers real-time, periodic, unicast request
opportunities, which meet the flow’s real-time needs
and allow the SS to specify the size of the desired
uplink transmission burst. This service requires more
request overhead than UGS, but supports variable
grant sizes for optimum data transport efficiency.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 4
5. WMAN, part 2
Non-real-time Polling Service (nrtPS)
UGS The Non-real-time Polling Service (nrtPS) is designed
UGS
to support non-real-time service flows that require
rtPS
rtPS variable size bursts in the uplink on a regular (but not
nrtPS
nrtPS strictly periodic) basis.
BE
BE Subscriber stations contend for bandwidth (for uplink
transmission) during contention request opportunities.
The availability of such opportunities is guaranteed at
regular intervals (on the order of one second or less)
irrespective of network load.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 5
6. WMAN, part 2
Best Effort (BE) service
UGS The Best Effort service is intended to be used for best
UGS
effort traffic where no throughput or delay guarantees
rtPS
rtPS are provided.
nrtPS
nrtPS
Subscriber stations contend for bandwidth (for uplink
BE
BE transmission) during contention request opportunities.
The availability of such opportunities depends on
network load and is not guaranteed (in contrast to
nrtPS).
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 6
7. WMAN, part 2
Radio Link Control in IEEE 802.16
The main task of Radio Link Control (RLC) in IEEE 802.16
systems is to provide dynamic changing of UL and DL burst
profiles on a per-connection and per-frame basis, depending
on radio channel characteristics and QoS requirements.
As an example, RLC provides signaling for initial access
(ranging) and bandwidth allocation in the downlink direction:
• Ranging request (RNG-REQ) from SS to BS
• Ranging response (RNG-RSP) from BS to SS
• Bandwidth requests (DBPC-REQ) from SS to BS
• Bandwidth confirmation (DBPC-RSP) from BS to SS
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 7
8. WMAN, part 2
Initial access (initial ranging)
RNG-REQ During initial access, the SS sends a ranging
RNG-RSP request message in the contention slot reserved
DBPC-REQ for this purpose, among others indicating which
DBPC-RSP kind of DL burst profile should be used.
Note: There is the possibility of collision since
other subscriber stations also send ranging
request messages in this contention slot.
… Contention Contention UL PHY
Contention Contention UL PHY UL PHY
UL PHY … UL traffic
slot A
slot A slot B
slot B burst 1
burst 1 burst 2
burst 2
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 8
9. WMAN, part 2
Initial access (initial ranging)
RNG-REQ In response to the RNG-REQ message, the BS
RNG-RSP returns a ranging response message in a DL
DBPC-REQ burst with a sufficiently robust burst profile.
DBPC-RSP
This message includes the timing advance value
for correct alignment of bursts in UL, as well as
UL power control information.
DL PHY
DL PHY
burst
burst
Preamble
Preamble FCS
FCS DL burst 1 … DL burst k … DL burst n
DL burst 1 DL burst k DL burst n
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10. WMAN, part 2
DL burst profile change
RNG-REQ The SS continuously measures the radio channel
RNG-RSP quality. If there is a need for change in DL burst
DBPC-REQ profile, the SS sends a DL burst profile change
DBPC-RSP request message in the contention slot reserved
for this purpose, indicating the desired new DL
burst profile.
… Contention Contention UL PHY
Contention Contention UL PHY UL PHY
UL PHY … UL traffic
slot A
slot A slot B
slot B burst 1
burst 1 burst 2
burst 2
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 10
11. WMAN, part 2
DL burst profile change
RNG-REQ In response to the DBPC-REQ message, the BS
RNG-RSP returns a DL burst profile change response
DBPC-REQ message confirming the new burst profile.
DBPC-RSP
This is done in a DL burst with the old burst
profile (when changing to a less robust DL burst
profile) or using the new burst profile (when
DL PHY
DL PHY changing to a more robust DL burst profile).
burst
burst
Preamble
Preamble FCS
FCS DL burst 1 … DL burst k … DL burst n
DL burst 1 DL burst k DL burst n
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 11
12. WMAN, part 2
Transition to a new DL burst profile
BS SS
Channel measurement indicates that DL burst profile n
DL burst profile n
different DL burst profile should be used is used
is used
DBPC-REQ
DBPC-REQ
DBPC-RSP
DBPC-RSP
DL data is sent using DL burst profile k
DL burst profile k
new burst profile k is used
is used
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 12
13. WMAN, part 2
UL burst profile change
RNG-REQ The BS measures the UL signal quality and may
RNG-RSP request a change in UL burst profile as indicated
DBPC-REQ in the downlink channel descriptor (DCD) within
DBPC-RSP the first DL burst of the DL PHY burst.
DCD
SS: Read DCD and change
SS: Read DCD and change
DL PHY
DL PHY
UL burst profile accordingly
UL burst profile accordingly
burst
burst
Preamble
Preamble FCS
FCS DL burst 1 … DL burst k … DL burst n
DL burst 1 DL burst k DL burst n
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 13
14. WMAN, part 2
Dynamic QoS management in practice
The request-response mechanism described on the previous
slides is designed to be scalable, efficient, and self-correcting.
While extensive bandwidth allocation and QoS mechanisms
are specified in the IEEE 802.16 standard, the details of
scheduling and reservation management have not been
standardized and thus provide an important mechanism for
vendors to differentiate their equipment.
(There is a similar situation regarding standardization of a
transmission system in general: the transmitted signal is
standardized in detail, whereas receivers can process the
received signal as they like, using innovative technology.)
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 14
15. WMAN, part 2
Three types of management connections
When a subscriber station acesses the network, three types of
management connections are established between the SS and
the BS (before transport connections can be established):
Basic management connection for exchange of short,
delay-critical MAC management messages
Primary management connection for exchange of longer,
more delay tolerant MAC management messages
Secondary management connection for exchange of delay
tolerant IP-based messages, such as used during DHCP
transactions.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 15
16. WMAN, part 2
Connection establishment (1)
Channel acquisition:
The MAC protocol includes an initialization procedure
designed to eliminate the need for manual configuration.
Upon installation, the SS scans for a suitable BS downlink
signal. The SS synchronizes to this signal and reads the
downlink channel descriptor (DCD) and uplink channel
descriptor (UCD) information in the first DL burst of the
DL PHY PDU, in order to learn the modulation and coding
schemes used on the carrier.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 16
17. WMAN, part 2
Connection establishment (2)
Initial ranging and negotiation of SS capabilities (1):
Upon learning what parameters to use for its initial
ranging signal in UL, the SS looks for initial ranging
opportunities by scanning the UL-MAP information present
in every frame.
After a random backoff time, the SS sends the ranging
request message (RNG-REQ) to the BS.
The BS calculates the timing advance value that the SS
must use in UL from now on, and sends this information
to the SS in the RNG-RSP message.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 17
18. WMAN, part 2
Connection establishment (3)
Initial ranging and negotiation of SS capabilities (2):
The BS also sends power control information, as well as
the CID for the basic management connection and the
primary management connection to the SS.
Using the primary management connection, the SS
reports its PHY capabilities, including the modulation and
coding schemes it supports and whether, in an FDD
system, it is half-duplex or full-duplex. The BS, in its
response, can deny the use of any capability reported by
the SS.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 18
19. WMAN, part 2
Connection establishment (4)
SS authentication (using privacy sublayer):
Each SS contains both a manufacturer-issued factory-
installed X.509 digital certificate and the certificate of the
manufacturer. After sending these certificates (and the
public key of the SS) to the BS, the BS can authenticate
the SS. If authentication is successful, the BS sends the
Authorization Key (AK), encrypted with the public key of
the SS, to the SS.
The AK is used both by SS and BS for securing further
information flow.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 19
20. WMAN, part 2
Connection establishment (5)
SS registration:
Upon successful authentication, the SS registers with the
network. The response from the BS contains the CID for a
secondary management connection. Contrary to the basic
and primary management connection, this secondary
management connection is secured.
At this point, the capabilities related to connection setup
and MAC operation, as well as the IP version used, are
determined. (Remember that the secondary management
connection is IP-based.)
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 20
21. WMAN, part 2
Connection establishment (6)
IP connectivity:
After registration, using the secondary management
connection, the SS is allocated an IP address via DHCP
and establishes the time of the day via the Internet Time
Protocol.
The DHCP server also provides the address of the TFTP
server from which the SS can request a configuration file.
This file provides a standard interface for providing
vendor-specific configuration information.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 21
22. WMAN, part 2
Connection establishment (7)
Connection setup:
Finally, the secondary management connection is also
used for setting up one or more transport connections.
These transport connections carry the actual user data
(IP traffic, VoIP traffic, etc.) between BS and SS.
IEEE 802.16 uses the concept of service flows to define
unidirectional transport of packets on either downlink or
uplink. Service flows are characterized by a certain set of
QoS parameters, and are established using a three-way
handshaking establishment procedure.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 22
23. WMAN, part 2
Summary: Dynamic QoS management
In summary, IEEE 802.16 offers the following mechanisms
for dynamically managing QoS and bandwidth:
In the PHY layer by adjusting the DL and UL burst profiles
(modulation and coding combination) on a per-frame basis.
In the MAC layer through fragmentation and packing (both
can be done at the same time).
At higher protocol layers by using scheduling algorithms in
the base station. These algorithms are not specified in the
IEEE 802.16 standard.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 23
24. WMAN, part 2
WirelessMAN-OFDM PHY
WirelessMAN-OFDM is based on 256 subcarriers, of which
200 subcarriers are used: 192 data subcarriers + 8 pilot
subcarriers. There are 56 ”nulls” (center carrier, 28 lower
frequency and 27 higher frequency guard carriers).
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 24
25. WMAN, part 2
Modulation and coding affect user data rate
The 192 data subcarriers carry 192 data symbols in parallel
(= transmitted at the same time). Each symbol carries 1 bit
(BPSK), 2 bits (QPSK), 4 bits (16-QAM), or 6 bits (64-QAM) of
channel information (corresponding to the channel bit rate
after channel coding, not to be confused with the user bit rate
before channel coding).
The inner convolutional coding reduces the usable number of
bits to 1/2, 2/3, or 3/4 of the channel information.
The outer Reed-Solomon block coding furthermore reduces
the usable number of bits about 10 %.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 25
26. WMAN, part 2
Subcarrier signal in time domain (1)
Guard time for preventing In the receiver, FFT is calculated
intersymbol interference only during this time
Tg Tb
Next symbol
Time
Ts
IEEE 802.16 offers four values for G = Tg/Tb: G = 1/4, 1/8,
1/16 or 1/32. (802.11a/g offers only one value: G = 1/4)
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 26
27. WMAN, part 2
Subcarrier signal in time domain (2)
Tg Tb
Next symbol
Time
IEEE 802.16 offers various bandwidth choices. The bandwidth is
typically an integer multiple of 1.25, 1.5 or 1.75 MHz.
(802.11a/g offers only a fixed channel bandwidth: 16.25 MHz)
Since the number of subcarriers is fixed, a certain bandwidth is
translated into a certain subcarrier spacing ∆f = 1/Tb.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 27
28. WMAN, part 2
Four primitive parameters
WirelessMAN-OFDM defines four "primitive parameters" that
characterize the OFDM symbol:
The nominal channel bandwidth BW
The number of used subcarriers Nused = 200
The sampling factor n. This parameter depends on the
bandwidth. For instance, when the bandwith is a multiple
of 1.25, 1.5 or 1.75 MHz, n = 144/125, 86/75 or 8/7,
respectively.
The guard time to useful symbol time ratio G.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 28
29. WMAN, part 2
Derived parameters
Using the four primitive parameters shown on the previous
slide, the following additional parameters can be derived:
NFFT (the smallest power of two greater than Nused) = 256
Sampling frequency fs = floor(n.BW/8000)x8000
Subcarrier spacing ∆f = fs/NFFT
Useful symbol time Tb = 1/∆f
Guard time Tg = G.Tb
OFDM symbol time Ts = Tg + Tb.
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 29
30. WMAN, part 2
Example
For BW = 5 MHz, BPSK, G = 1/32, calculate peak bit rate:
fs = floor(144/125 x 5 MHz / 8000) x 8000 = 5.76 MHz
∆f = fs/NFFT = 5.76 MHz / 256 = 22.5 kHz
Tb = 1/∆f = 44.44 µs
Tg = G.Tb = 1.39 µs 86.4 info bits / OFDM symbol
Ts = Tg + Tb = 45.83 µs
Peak bit rate = (192 bits x 0.5 x 0.9) / 45.83 µs
= 1.89 Mb/s
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 30
31. WMAN, part 2
Modulation and coding combinations
Modulation Coding Info bits / Info bits / Peak data
rate subcarrier symbol rate (Mbit/s)
BPSK 1/2 0.5 88 1.89
QPSK 1/2 1 184 3.95
QPSK 3/4 1.5 280 6.00
16-QAM 1/2 2 376 8.06
16-QAM 3/4 3 568 12.18
64-QAM 2/3 4 760 16.30
64-QAM 3/4 4.5 856 18.36
Depends on chosen bandwidth (here 5 MHz is assumed)
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 31
32. WMAN, part 2
Example (cont.)
The peak bit rate does not take into account the MAC layer
overhead (MAC PDU header and trailer) and PHY layer
overhead (contention slots and burst preamble in UL, DL PHY
PDU preamble and header in DL).
Consequently, the user data rate is substantially smaller
(even if the SS is the only user of the WMAN).
S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 32