Bridging the Homework Gap with Wireless Broadband

IEEE 802.16/WiMAX-based broadband and mobile wireless access is expected to be a significant component in the next generation (e.g., beyond 3G, 4G) wireless systems. IEEE 802.16/WiMAX standard, which incorporates several advanced radio transmission technologies such as orthogonal-frequency division multiplexing (OFDM), adaptive modulation and coding, and adaptive forward error correction (FEC), is designed to provide broadband wireless capability using a well-defined quality-of-service (QoS) framework. Therefore, this is a promising technology for wireless services requiring high- rate transmission (in the range of tens of Mbps) and strict QoS requirements in both indoor and outdoor environments. This technology is currently of big interest to researchers and practitioners involved in the design, analysis, installation, and management of mobile broadband wireless access systems and networks. The objective of this tutorial is to provide a complete overview on the IEEE 802.16/WiMAX standard and the current state-of-the-art research on the design, analysis, and optimization of IEEE802.16/WiMAX-based networks. The key technical challenges related to protocol engineering in these networks are described. The aim is to provide a survey on the emerging IEEE 802.16/WiMAX technology rather than an in-depth study on a specific protocol engineering problem. An overview of the different evolutions of the IEEE 802.16/WiMAX standard broadband wireless access (BWA) is presented and the open research issues in protocol engineering (e.g., for radio resource management, mobility support, security) are identified. A comprehensive survey on radio resource management, traffic scheduling, admission control, mobility management, and security mechanisms for IEEE 802.16/WiMAX are provided. A comparative performance study among the third-generation (3G) and the IEEE 802.16-based systems is provided. Several applications (e.g., wireless telemedicine and e-health services), services and deployment scenarios are described and the necessary protocol design and engineering issues are outlined.

There is a continuous demand for increasing wireless access broadband services to the end users, especially with widespread high quality mobile devices. The Internet mobile applications and multimedia services are constantly hungry for broadband wireless bandwidth. In order to overcome this bandwidth limitation, a frequency band (57-64 GHz) has recently been assigned for short range indoor wireless broadband signals due to the large available bandwidth. However, the transmission at this band is limited to a few meters due to the high atmospheric absorption loss. Radio over Fiber (RoF) technology was considered an efficient solution to extend the distribution range and wireless capacity services. This chapter presents an introduction to RoF technology and its basic required optical components for indoor short range wireless millimeter waves (mm-waves). The limiting factors of RoF and its impairments are also described. Moreover, optical mm-wave generation solutions are explained and followed by the recent optical 60GHz activities and upcoming research areas such as THz and optical wireless.

The rapid development of sophisticated military command and control systems causes the dynamic demand for broadband services including the transmission of video in real time by using telecommunications links. One way to resolve the problem of limited bandwidth in used military wireless systems is to use modern broadband radio stations. Broadband radio stations in addition to undoubted advantages such as increased system bandwidth, have also some limitations – in comparison to narrowband radios, broadband radios offer a smaller range and work in a wide band and high transmitter activity associated with the generation of maintenance traffic, which makes it easier to detect radio emission by the opponent. Modern electronic warfare systems can track down such systems and overpower them. That is why one of the main tasks, which currently are facing designers of advanced broadband radio communication systems, is to develop mechanisms to immunize broadband radio stations on the targeted interference. In this article the method of implementation of the national waveform allowing for securing the transmission in broadband radio stations will be presented. Transmission modes of the radio station (TDMA, CSMA/SC, CSMA/MC) will be discussed considering advantages and disadvantages of each of the above-mentioned modes of operation. In the next chapter selected results of experimental studies of broadband radio station R-450C with the above-mentioned implemented operating modes and universal defeat device for generation of diverse broadband interference will be presented. The obtained results will allow to assess the implemented modes of radio stations for resistances of broadband radio communication system on selected targeted interference. The developed analysis and obtained measurement results may be helpful both for people organizing radio communication using broadband radios as well as for those responsible for the proper operation of electronic warfare systems.

In the blink of an eye, you may miss the 350 km/h high-speed train as it thunders by, not mentioning the 574 km/h French TGV track train (April 2007) or the 581 km/h Japanese JR-Maglev train (December 2003). Recently, there have been growing interests to deliver true broadband wireless internet services to high-speed train passengers. To provide the broadband wireless services in such a high mobility environment, a number of technical challenges should be tackled, such as the severe Doppler shift problem, fast fading channel characteristics, fast power control and fast handover issues. The focus of this talk is on the anti-Doppler problem techniques, mobility management and network architecture. (Note: This work was partially supported by NSFC No. 60772087, 863 High-Tech R&D Program No.2009AA01Z238, 111 Project No.111-2-14 and MoST Sino-Swedish Joint Research NO.2008DFA12160).

In this paper, error resilience is achieved by adaptive, application-layer rateless channel coding, which is used to protect H.264/Advanced Video Coding (AVC) codec data-partitioned videos. A packetization strategy is an effective tool to control error rates and, in the paper, source-coded data partitioning serves to allocate smaller packets to more important compressed video data. The scheme for doing this is applied to real-time streaming across a broadband wireless link. The advantages of rateless code rate adaptivity are then demonstrated in the paper. Because the data partitions of a video slice are each assigned to different network packets, in congestion-prone wireless networks the increased number of packets per slice and their size disparity may increase the packet loss rate from buffer overflows. As a form of congestion resilience, this paper recommends packet-size dependent scheduling as a relatively simple way of alleviating the buffer-overflow problem arising from data-partitioned packets. The paper also contributes an analysis of data partitioning and packet sizes as a prelude to considering scheduling regimes. The combination of adaptive channel coding and prioritized packetization for error resilience with packet-size dependent packet scheduling results in a robust streaming scheme specialized for broadband wireless and real-time streaming applications such as video conferencing, video telephony, and telemedicine.

Coverage study for broadband wireless systems using link adaptation and diversity combining techniques

With the advent of next generation (4G) broadband wireless communications, the combination of multiple-input multiple-output (MIMO) wireless technology with orthogonal frequency division multiplexing (OFDM) has been recognized as one of the most promising techniques to support high data rate and high performance. In particular, coding over the space, time, and frequency domains provided by MIMO-OFDM will enable a much more reliable and robust transmission over the harsh wireless environment. In this article we provide an overview of space-time (ST) coding, space-frequency (SF) coding, and space-time-frequency (STF) coding for MIMO-OFDM systems. Performance results show that STF coding can achieve the maximum diversity gain in an end- to-end MIMO-OFDM system over broadband wireless channels. Furthermore, for orthogonal frequency division multiple access (OFDMA), we propose a multiuser SF coding scheme that can achieve the maximum diversity for each user while minimizing the interference introduced from all the other users.

As wireless devices and the useful services they can deliver become more pervasive and affordable; the need for wireless broadband technologies meeting the demands of emerging market countries is growing. In this paper the technology choice in wireless broadband access and service architecture is discussed with reference to three important wireless broadband technologies and relevant parameters such as service activation, authentication and delivery, cost effectiveness and sustainability. The main focus of the article is towards wireless broadband technology deployment in developing countries and rural communities for providing innovative wireless broadband services.

As the users' demand for informationization and mobile increasing, based on the development of wireless broadband technology, wireless cities in China are advancing to the implementation stage ahead. This paper attempts to take San Francisco for example to study the problems encountered by U.S. (United States) cities in the process of promoting public wireless broadband network, and the policies and results of solving them. Some proposals will be brought forward for the development of Chinese wireless. Keywords-wireless broadband internet; wireless broadband community

Overestimating Wireless Demand: Policy and Investment Implications of Upward Bias in Mobile Data Forecasts

This paper provides an assessment of wireless BB services drawing on Telstra's experience as an operator. It discusses the evolution of wireless technologies and the drivers for the building of Telstra's Next G® network, including the role devices have played. It also considers the growth of mobile service capability and future trends, such as the growth of both high bandwidth video services and low bandwidth but high volume Machine to Machine or M2M communications. Issues such as latency, interoperability and quality of coverage, and data usage per device are discussed. Finally the development and deployment of portable wireless broadband base stations for use in disaster areas and for locations of temporary increased demand is described.

Wireless network operators often offer wireless broadband services by using different wireless technologies such as WiMAX, WiFi and HSPA. Each wireless technology often uses a separate and stand alone network architecture, and thus operations and management may easily become a complex and expensive task. In this paper we present the design and implementation of an all-IP heterogeneous network where the services provided are public and private wireless broadband access based on Fixed WiMAX, WiFi and HSPA. These basic services and combinations of these are further used to design different commercial products in the network. Radio coverage measurements are then performed for these technologies in interesting parts of the realized deployed network. The overall network implementation has been in successful operation for several months.

IEEE 802.16 Wireless Broadband is a promising technology for providing last mile access. Quality of Service (QoS) is an important factor that has been addressed by the standard which defines four types of multimedia traffic classes. However resource allocation and scheduling between the traffic classes is vital in providing QoS which the standard has left undefined. In this paper we propose a queue based scheduling algorithm for real time and non real time traffic at the Medium Access Control (MAC) layer. The algorithm is based on resource sharing between real time and non real time traffic depending on their queue size and latency requirements. We have simulated various traffic scenarios by implementing the algorithm in QualNet WiMAX simulator and studied its performance.

Digital television is transforming both broadcasting and, as a result of convergence, the larger world of communications. The impending analogue switch-off will have a major impact on households all over the developed world. Digital Broadcasting considers the effects of digital television on the availability, price and nature of broadcast services in the Americas, Europe and Japan. It shows how this depends upon what platforms – cable, satellite, fixed or wireless broadband – countries have available for use and also upon government policies and regulatory interventions.

Digital television is transforming both broadcasting and, as a result of convergence, the larger world of communications. The impending analogue switch-off will have a major impact on households all over the developed world. Digital Broadcasting considers the effects of digital television on the availability, price and nature of broadcast services in the Americas, Europe and Japan. It shows how this depends upon what platforms – cable, satellite, fixed or wireless broadband – countries have available for use and also upon government policies and regulatory interventions.