Peter Bosch

Telco clouds and Virtual Telco: Consolidation, convergence, and beyond

In this position paper we introduce Virtual Telco, a comprehensive effort to simplify the management of deployed telecommunication services by using a Cloud computing approach. The main objective of Virtual Telco is to replace the costly dedicated hardware implementing several centralized control plane functions and other services with distributed solutions that may be allocated on-demand over a pool of dependable, dynamically contracted computing and networking resources that are easy to manage. Virtual Telco relies on state-of-the-art techniques in the domains of virtualization and distributed systems to meet the challenging criteria of reliability, scalability, and timeliness required by present and future telecommunication standards and services. As a representative example of a Virtual Telco application, we propose the case of the distributed mobility management entity (MME) for next-generation LTE cellular networks.

911-NOW: A network on wheels for emergency response and disaster recovery operations

Public safety organizations increasingly rely on wireless communication technology to provide effective command, control, and communication during emergencies and disaster response operations. Since emergencies can vary in scale from day-to-day operations to large-scale and widespread catastrophic events, any previously deployed network infrastructure may not be able to handle the traffic load. Worse, the wireless infrastructure may be damaged or destroyed, as occurred during the events of 9/11 and Hurricane Katrina. The 911-network on wheels (911-NOW) solution is a novel portable cellular system based on base station routers (BSRs) that does not require any pre-existing wireless infrastructure and provides capacity and coverage on demand. It is an auto-configurable system with a fully integrated service architecture that can be deployed as a single-cell solution for local communication or be configured to operate as an ad hoc network of cells. This paper describes the 911-NOW vision and discusses some of the differentiating features such as auto-configuration, network management, wireless mesh networking, and interoperability with existing public safety systems. We also highlight some of the research challenges associated with mobile and rapidly deployable wireless networks. In particular we provide an overview of issues centered upon dynamic assignment and management of Internet Protocol (IP) addresses, online and real-time calculation and maintenance of routing information, mobility management, and dynamic configuration and optimization of radio parameters.

The UMTS base station router

This paper reviews the Alcatel-Lucent Universal Mobile Telecommunications System (UMTS) base station router (BSR)—a radio access network (RAN) and core network (CN) in a single network element. While typical cellular UMTS networks are built from a plethora of network elements and are maintained in a hierarchical fashion, the BSR combines all functions of a radio access network and core network in a single network element. Moreover, the BSR can be considered a wireless edge router that bridges between cellular-specific wireless transmissions and IP networks. Integrating RAN functionality in a single network element presents the following technical advantages: improving the responsiveness (i.e., latency reductions), reducing the complexity, and improving the fault tolerance of the system.

Toward a Cloud Operating System

Cloud computing is characterized today by a hotchpotch of elements and solutions, namely operating systems running on a single virtualized computing environment, middleware layers that attempt to combine physical and virtualized resources from multiple operating systems, and specialized application engines that leverage a key asset of the cloud service provider (e.g. Googles BigTable). Yet, there does not exist a virtual distributed operating system that ties together these cloud resources into a unified processing environment that is easy to program, flexible, scalable, self-managed, and dependable. In this position paper, we advocate the importance of a virtual distributed operating system, a Cloud OS, as a catalyst in unlocking the real potential of the Cloud-a computing platform with seemingly infinite CPU, memory, storage and network resources. Following established Operating Systems and Distributed Systems principles laid out by UNIX and subsequent research efforts, the Cloud OS aims to provide simple programming abstractions to available cloud resources, strong isolation techniques between Cloud processes, and strong integration with network resources. At the same time, our Cloud OS design is tailored to the challenging environment of the Cloud by emphasizing elasticity, autonomous decentralized management, and fault tolerance.

Comparison of MME Signaling Loads for Long-Term-Evolution Architectures

The LTE architecture consists of eNBs that provide wireless connectivity to each UE, S-GWs that anchor the user plane for mobility, MMEs that provide control-plane support to each UE in its domain such as handover, paging, bearer management and tracking area updates and finally, PDNs that bridge the cellular network to the Internet. In this paper, we investigate LTE architectures with distributed MMEs and with a centralized MME. We present an analysis of the signaling load performance at the MME serving multimedia-capable UEs and compare the performance under both architectures. We propose a multicast paging procedure to alleviate the MME signaling load and compare the MME performance with multicast and unicast paging procedures. Our results show significant benefits of multicasting. I. INTRODUCTION

Clockwise: a mixed-media file system

This paper presents Clockwise, a mixed-media file system. The primary goal of Clockwise is to provide a storage architecture that supports the storage and retrieval of best-effort and real-time file system data. Clockwise provides an abstraction called a dynamic partition that groups lists of related (large) blocks on one or more disks. Dynamic partitions can grow and shrink in size and reading or writing of dynamic partitions can be scheduled explicitly. With respect to scheduling, Clockwise uses a novel strategy to pre-calculate schedule slack time and it schedules best-effort requests before queued real-time requests in this slack time.

Duplexing, resource allocation and inter‐cell coordination: design recommendations for next generation wireless systems

Coexistence of different access technologies, hierarchical cellular deployment, a wide variety of data services, requirements for transparent operation across different technologies, adaptivity to varying network conditions and mobility and quality of service (QoS) constraints introduce a number of challenges in the design of future generation systems and the specification of new air interfaces, such as efficiency and flexibility in the utilization of spectrum, dynamic resource allocation and exploitation of the multiuser diversity and reconfigurable interference management and inter-cell coordination. Three critical issues for the design of next generation systems are addressed: (i) duplexing, (ii) scheduling and resource allocation and (iii) interference and inter-cell coordination. A number of research directions are presented, which constitute promising potential candidates for next generation systems specification.

Mobility in UMTS packet IP networks

We have built a research prototype of UMTS access point called a UMTS IP router (UIP). This network element combines the hierarchy of GGSN, SGSN, RNC and NodeB in a single base station. The primary reason for integrating existing network elements into a single system is for performance. The UIP routes IP traffic from IP networks to IP capable UMTS terminals. Future transmission technologies rely on transmission in simplex using hybrid ARQ (H-ARQ). Todays UMTS networks, however, still rely on downlink soft handover and this has led to a hierarchical design. An alternative for the hierarchical design is one that combines the functionality of the typical cellular network elements into one wireless specific IP router. Since downlink diversity is no longer used when H-ARQ comes into play, giving up downlink soft handover does not constitute a performance penalty provided another, equally efficient handover method can be used in our flat cellular network design. In this paper we show that efficient hard handover is possible in a flat architecture and that giving up the hierarchical design allows us to (1) remove unnecessary protocol layers from the UMTS protocol stack; and (2) reduce the end-to-end latency of wireless transmission by abolishing UMTS base station synchronization. While our current prototype does not yet support HSDPA, the penalty for giving up downlink diversity is compensated by the large reductions in transmission delays

“Don't hide power”

A standard PC today has an I/O throughput in excess of 100MBps. It can, therefore, be used as a continuous-media server. Since PC hardware is also cheap, it is surprising that not many continuous-media servers today are built on PC hardware. This paper describes two things. First, we give a summary of I/O measurements on a 200MHz Pentium-Pro based machine. Second, we present the design and implementation of a continuousmedia server called Clockwise whose design was partially dictated by the measured characteristics of nthe hardware.