Is re-farming the answer to the spectrum shortage conundrum?

Radio spectrum has become one of the engines of economic growth. However, rapid technological change, ever increasing demands for new wireless services and the nature of spectrum as a scarce resource necessitate an urgent re-examination of issues such as congestion and interference. This paper argues that the traditional administrative spectrum management approach is unlikely to overcome these issues, thereby resulting in growing technical and economic inefficiencies. As countries review their spectrum policies - a process that is generically referred to as radio spectrum policy reform - to counter these inefficiencies, modifications to the radio frequency allocations and assignments are beginning to be implemented by way of radio spectrum re-farming? This phenomenon forms the subject matter of this paper

Datacenter Traffic Control: Understanding Techniques and Trade-offs

Datacenters provide cost-effective and flexible access to scalable compute and storage resources necessary for today's cloud computing needs. A typical datacenter is made up of thousands of servers connected with a large network and usually managed by one operator. To provide quality access to the variety of applications and services hosted on datacenters and maximize performance, it deems necessary to use datacenter networks effectively and efficiently. Datacenter traffic is often a mix of several classes with different priorities and requirements. This includes user-generated interactive traffic, traffic with deadlines, and long-running traffic. To this end, custom transport protocols and traffic management techniques have been developed to improve datacenter network performance. In this tutorial paper, we review the general architecture of datacenter networks, various topologies proposed for them, their traffic properties, general traffic control challenges in datacenters and general traffic control objectives. The purpose of this paper is to bring out the important characteristics of traffic control in datacenters and not to survey all existing solutions (as it is virtually impossible due to massive body of existing research). We hope to provide readers with a wide range of options and factors while considering a variety of traffic control mechanisms. We discuss various characteristics of datacenter traffic control including management schemes, transmission control, traffic shaping, prioritization, load balancing, multipathing, and traffic scheduling. Next, we point to several open challenges as well as new and interesting networking paradigms. At the end of this paper, we briefly review inter-datacenter networks that connect geographically dispersed datacenters which have been receiving increasing attention recently and pose interesting and novel research problems.Comment: Accepted for Publication in IEEE Communications Surveys and Tutorial

Market driven network neutrality and the fallacies of internet traffic quality regulation

In the U.S. paying for priority arrangements between Internet access service providers and Internet application providers to favor some traffic over other traffic is considered unreasonable discrimination. In Europe the focus is on minimum traffic quality requirements. It can be shown that neither market power nor universal service arguments can justify traffic quality regulation. In particular, heterogeneous demand for traffic quality for delay sensitive versus delay insensitive applications requires traffic quality differentiation, priority pricing and evolutionary development of minimal traffic qualities.

Market driven network neutrality and the fallacies of Internet traffic quality regulation

In the U.S. paying for priority arrangements between Internet access service providers and Internet application providers to favor some traffic over other traf-fic is considered unreasonable discrimination. In Europe the focus is on mini-mum traffic quality requirements. It can be shown that neither market power nor universal service arguments can justify traffic quality regulation. In particular, heterogeneous demand for traffic quality for delay sensitive versus delay insen-sitive applications requires traffic quality differentiation, priority pricing and evolutionary development of minimal traffic qualities. --