William Lehr

Wireless Internet access: 3G vs. WiFi?☆

This article compares and contrasts two technologies for delivering broadband wireless Internet access services: ‘‘3G’’ vs. ‘‘WiFi’’. The former, 3G, refers to the collection of third-generation mobile technologies that are designed to allow mobile operators to offer integrated data and voice services over mobile networks. The latter, WiFi, refers to the 802.11b wireless Ethernet standard that was designed to support wireless LANs. Although the two technologies reflect fundamentally different service, industry, and architectural design goals, origins, and philosophies, each has recently attracted a lot of attention as candidates for the dominant platform for providing broadband wireless access to the Internet. It remains an open question as to the extent to which these two technologies are in competition or, perhaps, may be complementary. If they are viewed as in competition, then the triumph of one at the expense of the other would be likely to have profound implications for the evolution of the wireless Internet and structure of the service-provider industry. r 2003 Elsevier Science Ltd. All rights reserved.

COGNITIVE RADIOS FOR DYNAMIC SPECTRUM ACCESS - The Path to Market Success for Dynamic Spectrum Access Technology

Rapid progress is being made in the technology for dynamic spectrum access (DSA) radio systems. However, the structure and dynamics of the wireless services market must also evolve for DSA to succeed. This article examines the interlinked technical and economic issues associated with markets for DSA-based wireless services. We use this analysis to make technical and policy recommendations supporting the commercial success of DSA technology

Managing shared access to a spectrum commons

The open access, unlicensed or spectrum commons approach to managing shared access to RF spectrum offers many attractive benefits, especially when implemented in conjunction with and as a complement to a regime of market-based, flexible use, tradable licensed spectrum ([Benkler02], [Lehr04], [Werbach03]). However, as a number of critics have pointed out, implementing the unlicensed model poses difficult challenges that have not been well-addressed yet by commons advocates ([Benjam03], [Faulhab05], [Goodman04], [Hazlett01]). A successful spectrum commons will not be unregulated, but it also needs not be command & control by another name. This paper seeks to address some of the implementation challenges associated with managing a spectrum commons. We focus on the minimal set of features that we believe a suitable management protocol, etiquette, or framework for a spectrum commons will need to incorporate. This includes: (1) No transmit only devices; (2) Power restrictions; (3) Common channel signaling; (4) Mechanism for handling congestion and allocating resources among users/uses in times of congestion; (5) Mechanism to support enforcement (e.g., established procedures to verify protocol is in conformance); (6) Mechanism to support reversibility of policy; and (7) Protection for privacy and security. We explain why each is necessary, examine their implications for current policy, and suggest ways in which they might be implemented. We present a framework that suggests a set of design principles for the protocols that will govern a successful commons management regime. Our design rules lead us to conclude that the appropriate Protocols for a Commons will need to be more liquid ([Reed05]) than in the past: (1) Market-based instead of C&C; (2) Decentralized/distributed; and, (3) Adaptive and flexible (Anonymous, distributed, decentralized, and locally responsive)

Wireless is changing the policy calculus for municipal broadband

Historically, the justification for municipal provisioning of “last-mile” communications infrastructure has focused on the natural monopoly aspect of wireline infrastructure. Growing interest in wireless ISPs, municipal hot spots, and access to public space for siting wireless infrastructure suggests new and expanded opportunities for local government participation in telecommunication services. This paper examines the implications of emerging wireless technologies for the policy debate over whether municipalities should be playing an active role in providing last-mile broadband services and, if so, what the nature of that role should be.

Sensing as a Service: An Exploration into Practical Implementations of DSA

The cognitive radio literature generally assumes that the functions required for non-cooperative secondary DSA are integrated into a single radio system. It need not be so. In this paper, we model cognitive radio functions as a value chain and explore the implications of different forms of organization of this value chain. We initially explore the consequences of separating the sensing function from other cognitive radio functions.

Standardization : understanding the process

Critics of the CCITT, ISO, ANSI, X3, IEEE, and other standards development organizations (SDOs) complain that the formal approach to standard setting followed by these institutions is too bureaucratic and time consuming. This article describes the key features which distinguish SDO standard setting and analyzes these features in light of recent work in political economy. Many of the features which lead to a slower process may be interpreted as an efficient institutional response to the problems posed by industry standardization. A better understanding of the motivation behind the design of formal SDOs is essential if we are to improve existing processes.

Evolving wireless access technologies for municipal broadband

In recent years, the landscape for wireless technology has changed substantially, with profound implications for the evolution of last-mile access infrastructure. This paper provides a high-level introduction to emerging trends in wireless technology, with a special focus on how these are impacting municipal broadband deployments. This paper discusses some of the key architectural and design choices for wireless networking systems and their implications for cost and system performance. In addition, we provide examples of how the new wireless technologies are being deployed by municipalities in a variety of contexts, with reference to wireless technologies currently available from vendors. The policy implications of these trends are discussed further in a companion paper in this issue. I.

Time-limited leases in radio systems [Topics in Radio Communications]

A time-limited lease is a set of rights that expires after a specified duration. We analyze ways to use leases to facilitate innovation in radio devices and wireless communication. In our vision, manufacturers include in their devices a simple, secure subsystem that contains a clock and disables specific transmit capabilities if no extension message is received by the end of the lease period. When devices provide this support, regulators may use certification leases rather than permanent grants to accelerate deployment of innovative radios. Spectrum rights holders may use leases to reduce risk in secondary spectrum market transactions. Firms collaborating in innovative wireless service business models can better retain control of their respective rights. We examine both the technical and policy issues associated with leases.

An Overview of Dynamic Spectrum Sharing: Ongoing Initiatives, Challenges, and a Roadmap for Future Research

We are in the midst of a major paradigm shift in how we manage radio spectrum. This paradigm shift is necessitated by the growth of wireless services of all types and the demand pressure imposed on limited spectrum resources under legacy management regimes. The shift is feasible because of advances in radio and networking technologies that make it possible to share spectrum dynamically in all possible dimensions-i.e., across frequencies, time, location, users, uses, and networks. Realizing the full potential of this shift to Dynamic Spectrum Sharing will require the co-evolution of wireless technologies, markets, and regulatory policies; a process which is occurring on a global scale. This paper provides a current overview of major technological and regulatory reforms that are leading the way toward a global paradigm shift to more flexible, dynamic, market-based ways to manage and share radio spectrum resources. We focus on current efforts to implement database-driven approaches for managing the shared co-existence of users with heterogeneous access and interference protection rights, and discuss open research challenges.

On the convergence of wired and wireless access network architectures

Wired and wireless access networks continue to evolve toward higher-capacity, multi-service systems. Recent wireless broadband networks such as 3G LTE and WiMax provide a general-purpose IP platform with over-the-top services at the application layer, which is similar to the design of wired IP platform networks. This paper examines whether wired and wireless access networks are likely to converge on a common architecture, or if not, whether wireless networks are likely to converge on a common wireless architecture. We conclude that the answer to both questions is No. We identify fundamental and persistent differences between wired and wireless networking that will propel wired and wireless access network architectures on divergent evolutionary paths. Whereas we expect wired broadband access networks to continue to evolve toward a common general-purpose platform architecture, we expect wireless networks to remain heterogeneous. The inherent scarcity of radio frequency spectrum emerges as the key reason for this prediction. We examine the implications of divergent evolutionary paths for market structure and regulatory policy.