Abstract
We present deterministic and randomized algorithms for the problem of online packet routing in grids in the competitive network throughput model (Aiello et al. in SODA, pp 771–780 2003). In this model the network has nodes with bounded buffers and bounded link capacities. The goal in this model is to maximize the throughput, i.e., the number of delivered packets. Our deterministic algorithm is the first online algorithm with an Oleft( log ^{O(1)}(n)right) competitive ratio for uni-directional grids (where n denotes the size of the network). The deterministic online algorithm is centralized and handles packets with deadlines. This algorithm is applicable to various ranges of values of buffer sizes and communication link capacities. In particular, it holds for buffer size and communication link capacity in the range [3 ldots log n]. Our randomized algorithm achieves an expected competitive ratio of O(log n) for the uni-directional line. This algorithm is applicable to a wide range of buffer sizes and communication link capacities. In particular, it holds also for unit size buffers and unit capacity links. This algorithm improves the best previous O(log ^2 n)-competitive ratio of Azar and Zachut (ESA, pp 484–495, 2005).
Highlights
Large scale communication networks partition messages into packets so that high bandwidth links can support multiple sessions simultaneously
We present deterministic and randomized algorithms for the problem of online packet routing in grids in the competitive network throughput model (Aiello et al in SODA, pp 771–780 2003)
Requests for routing packets arrive over time, calling for the development of online packet routing algorithms
Summary
Large scale communication networks partition messages into packets so that high bandwidth links can support multiple sessions simultaneously. The development of algorithms that can route packets between different pairs of nodes is a fundamental problem in networks. Requests for routing packets arrive over time, calling for the development of online packet routing algorithms. The holy grail of packet routing is to develop online distributed algorithms whose performance is competitive with respect to multiple criteria, such as: throughput (i.e., deliver as many packets as possible), delay (i.e., guarantee arrival of packets on time), stability (e.g., constant rate, avoid buffer overflow) , fairness (i.e., fair sharing of resources among users), etc. The goal is to route packets (i.e., constant length formatted data) in a network of n nodes. Nodes in this model are switches with local memories called buffers. The buffer size is the maximum number of packets that can be stored in a node
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