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Towards Carrier-Grade Quality in Heterogeneous Wireless Mesh Networks
No full textCurrent backhaul networks typically comprise a wired middle mile and a wireless last mile part. The wireless part is almost exclusively based on tree topologies. However, a lot could be gained by deploying mesh-based backhauls. Meshes allow better network capacity exploitation due to load balancing and offer inherent resilience to link degradations or failures. Yet meshes come with increased complexity in terms of radio configuration, routing, or mobility management. This chapter proposes architecture and mechanisms for carrier-grade mesh-based wireless backhauls. One special focus is that it supports heterogeneous backhauls, which encompass multiple different wireless technologies. The proposition has been successfully deployed in a test network.TRUEpu
Multiple Daily Base Station Switch-Offs in Cellular Networks
Get PDFIn this paper we study base station sleep modes, which are today considered a viable approach to improve the energy efficiency of cellular access networks, by reducing power consumption in periods of low traffic. When some base stations are switched off, radio coverage and service provisioning are taken care of by the base stations that remain active, so as to guarantee that service is available over the whole area at all times. This is a realistic assumption in the case of the dense base station layouts of urban areas, which consume most of the network energy. We develop simple analytical models that allow optimal base station switch-off times to be identified as a function of the daily traffic pattern, in the cases in which either just one switch-off per day is possible (bringing the network from a high-power, fully-operational configuration, to a low-power reduced configuration), or several switch-offs per day are permitted (progressively reducing the number of active base stations and the network power). We first assume that any fraction of base stations can be switched off, then we consider a realistic case. We quantify the percentage of energy which can be saved with base station sleep modes, proving that it can be close to 50% of the total network energy consumption.TRUEpu
Temporal Rate Limiting: cloud elasticity at a flat fee
Get PDFIn the current usage-based pricing scheme offered
by most cloud computing providers, customers are charged based on the capacity and the lease time of the resources they capture(bandwidth, number of virtual machines, lOPS rate, etc.). Taking advantage of this pricing scheme, customers can implement auto-scaling purchase policies by leasing (e.g., hourly) necessary amounts of resources to satisfy a desired QoS threshold under their current demand. Auto-scaling yields strict QoS and variable charges. Some customers, however, would be willing to settle for a more relaxed statistical QoS in exchange for a predictable fiat
charge. In this work we propose Temporal Rate Limiting(TRL),
a purchase policy that permits a customer to allocate optimally a specified purchase budget over a predefined period of time. TRL offers the same expected QoS with auto-scaling but at a lower,flat charge. It also outperforms in terms of QoS a naive flat charge policy that splits the available budget uniformly in time. We quantify the benefits of TRL analytically and also deploy TRL
on Amazon Ee2 and perform a live validation in the context of a "blacklisting" application for Twitter.TRUEpu
Loop-Free Alternate (LFA) Applicability in Service Provider (SP) Networks
Get PDFLFA Applicability:
Pierre Francois was the editor of RFC 6571 [2], "LFA applicability in SP networks", co-edited with Clarence Filsfils, distinguished engineer at Cisco Systems. This RFC presents an analysis of the applicability of an IP Fast Reroute technique called "Loop-free alternates" in Internet Service Provider Networks. This work has been performed in collaboration with Cisco Systems, France Telecom - Orange, AT&T, and Deutsche Telekom.In this document, we analyze the applicability of the Loop-Free Alternate (LFA) method of providing IP fast reroute in both the core and access parts of Service Provider networks. We consider both the link and node failure cases, and provide guidance on the applicability of LFAs to different network topologies, with special emphasis on the access parts of the network.Internet Engineering Task Force (IETF)pu
Proceedings of the 3rd International Conference on Energy-Efficient Computing and Networking, e-Energy'12, Madrid, Spain, May 9-11, 2012
No full textTRUEpu
AIST: Insights into Queuing and Loss on Highly Multiplexed Links
Get PDFIn explicit or delay-driven congestion control, a common objective is to sustain high throughput without long queues and large losses at the bottleneck link of the network path. Congestion control protocols strive to achieve this goal by transmitting smoothly in the steady state. The discovery of the appropriate steady-state transmission rates is a challenging task in itself and typically introduces additional queuing and losses. Seeking insights into the steady-state profiles of queuing and loss achievable by real protocols, this paper presents an AIST (Asynchronous arrivals with Ideally Smooth Transmission) model that abstracts away transient queuing and losses related to discovering the path capacity and redistributing it fairly among the packet flows on the bottleneck link. In AIST, the flows arrive asynchronously but transmit their packets at the same constant rate in the steady state. For the link with an overprovisioned buffer, our queuing-theoretic analysis and simulations for different smooth distributions of packet interarrival times agree that queuing under AIST with the target utilization of 1 is on the order of the square root of N, where N is the number of flows. With small buffers, our simulations of AIST show an ability to provide bounded loss rates regardless of the number of flows.TRUEpu
Energy-Efficient Network Routing with Discrete Cost Functions
Get PDFEnergy consumption is an important issue in the design and
use of networks. In this paper, we explore energy savings in networks via a rate adaptation model. This model can be represented by a cost-minimization network routing problem with discrete cost functions. We formulate this problem as an integer program, which is proved to be NP-hard. Then a constant approximation algorithm is developed. In our proposed method, we first transform the program into a continuous-cost network routing problem, and then we approximate the optimal solution by a two-step rounding process. We show by analysis that, for uniform demands, our method provides a constant approximation for the uniform
network routing problem with discrete costs. A bicriteria network routing problem is also developed so that a trade-off can be made between energy consumption and network delay. Analytical results for this latter model
are also presented.TRUEpu
T4P: Hybrid Interconnection for Cost Reduction
Get PDFEconomic forces behind the Internet evolution have
diversified the types of ISP (Internet Service Provider) interconnections. In particular, settlement-free peering and paid peering proved themselves as effective means for reducing ISP costs. In this paper, we propose T4P (Transit for Peering), a new type of hybrid bilateral ISP relationships that continues the Internet trend towards more flexible interconnections at lower costs. With a T4P interconnection, one ISP compensates the other ISP for their peering by providing this other ISP with a partial transit service. In comparison to paid peering, T4P is able to reduce the combined transit/peering costs of an ISP due to the subadditive nature of transit billing. As a cost-effective alternative to existing interconnection types, T4P expands and strengthens the connectivity of the Internet, e.g., between content and eyeball networks. After analyzing incentives of ISPs to adopt T4P, we use
real traffic data from several IXPs (Internet eXchange Points) to quantify the T4P economic benefits. Our evaluation confirms the promising potential of T4P.TRUEpu
