Innovation in the Wireless Ecosystem: A Customer-Centric Framework

The Federal Communications Commission’s Notice of Inquiry in GN 09-157 Fostering Innovation and Investment in the Wireless Communications Market is a significant event at an opportune moment. Wireless communications has already radically changed the way not only Americans but people the world over communicate with each other and access and share information, and there appears no end in sight to this fundamental shift in communication markets. Although the wireless communications phenomenon is global, the US has played and will continue to play a major role in the shaping of this market. At the start of a new US Administration and important changes in the FCC, it is most appropriate that this proceeding be launched.

Spectrum Management: Property Rights, Markets, and The Commons

Gerald Faulhaber and David Farberconsider alternatives to the current licensing regime for spectrum, which appears to lead to substantial inefficiencies in spectrum allocation.Specifically, they examine two property rights regimes and a commons regime.Theynote that economists have favored a market-based regime while engineers have favored a commons-based regime to promote new technologies. Mr. Faulhaber and Mr. Farbershow that thereis aproperty rights market-based regime that unleashes the power of the market andthe power of the new technologies to efficiently allocate spectrum, and that is likely to meet our needs for the near-term future. This regime resolves the presumed dichotomy between the market-based and the commons-based views, so that both objectives can be realized.The authorsalso outline a transition processfor achieving the desired regime outcome that is a "win-win" for all stakeholders, and that could be politically feasible. The change to a property rights regime is likely to lower the cost of spectrum substantially, in many cases to zero.Mr. Faulhaber and Mr. Farberassert that a commons model and a market model can co-exist, at least until spectrum becomes truly scarce.

A distributed computer system

The goal of this project Is to plan and develop a computing system that will provide interactive computing services with a high degree of reliability, a variety of language systems, incremental expansion capability, competitive costs, a respect for human factors considerations; and the project will require only a modest amount of system programming resources

Congestion Control by Bandwidth-Delay Tradeoff in Very High-Speed Networks: The Case of Window-Based Control

Increasing bandwidth-delay product of high-speed wide-area networks is well-known to make conventional dynamic traffic control schemes sluggish . Still, most existing schemes employ dynamic control, among which TCP and ATM Forum\u27s rate-based flow control are prominent examples. So far, little has been investigated as to how the existing schemes will scale as bandwidth further increases up to gigabit speed and beyond. Our investigation in this paper is the first to show that dynamic control has a severe scalability problem with bandwidth increase, and to propose an entirely new approach to traffic control that overcomes the scalability problem. The essence of our approach is in exercising control in bandwidth domain rather than time domain, in order to avoid time delay in control. This requires more bandwidth than the timed counterpart, but achieves a much faster control. Furthermore, the bandwidth requirement is not excessively large because the bandwidth for smaller control delay and we call our approach Bandwidth-Latency Tradeoff (BLT). While the control in existing schemes are bound to delay, BLT is bound to bandwidth. As a fallout, BLT scales tied to bandwidth increase, rather than increasingly deteriorate as conventional schemes. Surprisingly, our approach begins to pay off much earlier than expected, even from a point where bandwidth-delay product is not so large. For instance, in a roughly AURORA-sized network, BLT far outperforms TCP on a shared 150Mbps link, where the bandwidth-delay product is around 60KB. In the other extreme where bandwidth-delay product is large, BLT outperforms TCP by as much as twenty times in terms of network power in a gigabit nationwide network. More importantly, BLT is designed to continue to scale with bandwidth increase and the performance gap is expected to widen further

The Mether System: Distributed Shared Memory for SunOS 4.0

Mether is a Distributed Shared memory (DSM) that runs on Sun workstations under the SunOS 4.0 operating system. User programs access the Mether address space in a way indistinguishable from other memory. Mether was inspired by the MemNet DSM, but unlike MemNet Mether consists of software communicating over a conventional Ethernet. The kernel part of Mether actually does no data transmission over the network. Data transmission is accomplished by a user-level server. The kernel driver has no preference for a server, and indeed does not know that servers exist. The kernel driver has been made very safe, and in fact panic is not in its dictionary

Reducing Host Load, Network Load and Latency in a Distributed Shared Memory

Mether is a Distributed Shared Memory (DSM) that runs on Sun¹ workstations under the SunOS 4.0 operating system. User programs access the Mether address space in a way indistinguishable from other memory. Mether had a number of performance problems which we had also seen on a distributed shared memory called Memnet[2]. In this paper we discuss changes we made to Mether and protocols we developed to use Mether that minimize host load, network load, and latency. An interesting (and unexpected) result was that for one problem we studied the same best protocol for Mether is identical to the best protocol for MemNet[6]. The changes to Mether involve exposing an inconsistent store to the application and making access to the consistent and inconsistent versions very convenient; providing both demand-driven and data-driven semantics for updating pages; and allowing the user to specify that only a small subset of a page need be transferred. All of these operations are encoded in a few address bits in the Mether virtual address

MIRAGE: A Model for Ultra-High-Speed Protocol Analysis and Design

Current protocols are expected to become inefficient if used at speeds in excess of 1 Gigabit per second. While this premise is widely accepted, no model exists to explain the phenomenon. We define a model for understanding protocols which is aimed at explaining why such a barrier exists, and indicates alternate designs which do not have this limit. Existing protocols are akin to classical mechanics; 1 Gigabit/second is the speed near which relativistic effects emerge. In order to account for these effects, we need to express knowledge at a distance, latent measurement, and uncertainty as real entities, not negligible estimates. The result is a model which expresses not only existing protocols, and may contribute to a better understanding of the Gigabit communications domain

Traffic Characteristics of a Distributed Memory System

We believe that many distributed computing systems of the future will use distributed shared memory as a technique for interprocess communication. Thus, traffic generated by memory requests will be a major component of the traffic for any networks which connect nodes in such a system. In this paper, we study memory reference strings gathered with a tracing program we devised. We study several models. First, we look at raw reference data, as would be seen if the network were a backplane. Second, we examine references in units of blocks , first using a one-block cache model and then with an infinite cache. Finally, we study the effect of predictive prepaging of these blocks on the traffic. We provide a novel representation of memory reference data which can be used to calculate interarrival distributions directly. Integrating communication with computation can be used to control both traffic and performance

Consistency Management in the EROS Kernel

EROS is a persistent operating system targeted towards managing resources with great longevity. The system provides a persistent single level store supporting two fundamental object types: nodes and pages. All primary objects, including memory segments and protection domains, are constructed out of these fundamental objects, and inherit their persistence. EROS is a pure capability system: access to objects is provided exclusively through the invocation of kernel enforced, secure capabilities. This paper describes the EROS Abstract Machine and the mechanisms used to achieve efficient consistency management within the system. The implementation, including all primary objects, a low overhead checkpoint/migration subsystem, and an efficient interprocess communication mechanism, requires less than 64 Kbytes of supervisor code (prior to size tuning)

A Secure and Reliable Bootstrap Architecture

In a computer system, the integrity of lower layers is treated as axiomatic by higher layers. Under the presumption that the hardware comprising the machine (the lowest layer) is valid, integrity of a layer can be guaranteed if and only if: (1) the integrity of the lower layers is checked, and (2) transitions to higher layers occur only after integrity checks on them are complete. The resulting integrity chain inductively guarantees system integrity. When these conditions are not met, as they typically are not in the bootstrapping (initialization) of a computer system, no integrity guarantees can be made. Yet, these guarantees are increasingly important to diverse applications such as Internet commerce, intrusion detection systems, and active networks. In this paper, we describe the AEGIS architecture for initializing a computer system. It validates integrity at each layer transition in the bootstrap process. AEGIS also includes a recovery process for integrity check failures, and we show how this results in robust systems. We discuss our prototype implementation for the IBM personal computer (PC) architecture, and show that the cost of such system protection is surprisingly small