scholarly journals Reinforcement Learning-Based Routing Algorithm in Satellite-Terrestrial Integrated Networks

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yabo Yin ◽  
Chuanghe Huang ◽  
Dong-Fang Wu ◽  
Shidong Huang ◽  
M. Wasim Abbas Ashraf ◽  
...  
Keyword(s):  
Routing Algorithm ◽  
Routing Algorithms ◽  
Convergence Speed ◽  
Satellite Network ◽  
Communication Services ◽  
Integrated Network ◽  
Routing Problem ◽  
Integrated Networks ◽  
Q Learning ◽  
Speed Up

Satellite-terrestrial integrated network (STIN) is an indispensable component of the Next Generation Internet (NGI) due to its wide coverage, high flexibility, and seamless communication services. It uses the part of satellite network to provide communication services to the users who cannot communicate directly in terrestrial network. However, existing satellite routing algorithms ignore the users’ request resources and the states of the satellite network. Therefore, these algorithms cannot effectively manage network resources in routing, leading to the congestion of satellite network in advance. To solve this problem, we model the routing problem in satellite network as a finite-state Markov decision process and formulate it as a combinatorial optimization problem. Then, we put forth a Q-learning-based routing algorithm (QLRA). By maximizing users’ utility, our proposed QLRA algorithm is able to select the optimal paths according to the dynamic characteristics of satellite network. Considering that the convergence speed of QLRA is slow due to the routing loop or ping-pong effect in the process of routing, we propose a split-based speed-up convergence strategy and also design a speed-up Q-learning-based routing algorithm, termed SQLRA. In addition, we update the Q value of each node from back to front in the learning process, which further accelerate the convergence speed of SQLRA. Experimental results show that our improved routing algorithm SQLRA greatly enhances the performance of satellite network in terms of throughput, delay, and bit error rate compared with other routing algorithms.

scholarly journals V2V Routing in VANET Based on Fuzzy Logic and Reinforcement Learning

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wanli Zhang ◽  
Xiaoying Yang ◽  
Qixiang Song ◽  
Liang Zhao
Keyword(s):  
Fuzzy Logic ◽  
Real Time ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Routing Algorithm ◽  
Cluster Head ◽  
Convergence Speed ◽  
Q Learning ◽  
On The Road ◽  
The Impact

To ensure the transmission quality of real-time communications on the road, the research of routing protocol is crucial to improve effectiveness of data transmission in Vehicular Ad Hoc Networks (VANETs). The existing work Q-Learning based routing algorithm, QLAODV, is studied and its problems, including slow convergence speed and low accuracy, are found. Hence, we propose a new routing algorithm FLHQRP by considering the characteristics of real-time communication in VANETs in the paper. The virtual grid is introduced to divide the vehicle network into clusters. The node’s centrality and mobility, and bandwidth efficiency are processed by the Fuzzy Logic system to select the most suitable cluster head (CH) with the stable communication links in the cluster. A new heuristic function is also proposed in FLHQRP algorithm. It takes cluster as the environment state of heuristic Q-learning, by considering the delay to guide the forwarding process of the CH. This can speed up the learning convergence, and reduce the impact of node density on the convergence speed and accuracy of Q-learning. The problem of QLAODV is solved in the proposed algorithm since the experimental results show that FLHQRP has many advantages on delivery rate, end-to-end delay, and average hops in different network scenarios.

Boolean Satisfiability Methods for Modern Computer-Aided Design Problems in Microelectronics

2020 ◽  
Vol 25 (6) ◽  
pp. 525-538
Author(s):  
M.A. Zapletina ◽  
◽  
D.V. Zhukov ◽  
S.V. Gavrilov ◽  
◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Digital Circuits ◽  
Routing Algorithm ◽  
Routing Algorithms ◽  
Boolean Satisfiability ◽  
Optimization Techniques ◽  
Design Flow ◽  
Equivalence Checking ◽  
Routing Problem ◽  
Operation Speed

Currently, the methods based on a Boolean satisfiability (SAT) problem are one of the efficient approaches to solving the problem of Boolean matching and the equivalence checking of digital circuits. In combination with classic routing algorithms and optimization techniques, the SAT methods demonstrate the results exceeding the classic routing algorithms by the operation speed and the quality of obtained results. In the paper, the analysis of the modern practice of using the SAT methods in the CAD systems for VLSI has been performed. The examples of modern SAT approaches to the problems of the formal equivalence checking of digital circuits descriptions within the technological mapping framework and to the routing problem as a part of the FPGA design flow have been considered. The algorithm of the detailed routing of the FPGA switching blocks using the satisfiability problem has been developed and presented. The results of its work have been demonstrated on the example of the programmable logic block of the domestic made integrated circuit 5400TP094. The block has the island architecture, where the configurable logic blocks and switching blocks form a regularly repeated layout template. The properties of the chosen classic architecture permit to expand the region of presented algorithm to the entire class of island style FPGA. The algorithm has been tested on the project benchmarks ISCAS-85, ISCAS-89 and LGSynth-89. The comparison of the developed SAT-based algorithm with the well-known routing algorithm Pathfinder by criteria of the elapsed time and the achieved portion of routed nets in the switching blocks is presented. It has been determined that the considered Boolean satisfiability methods for the routing problem are capable to prove the circuit unroutability, unlike the algorithm Pathfinder which results can only implicitly indicate it. The paper demonstrates that the application of more efficient SAT solver significantly accelerates work of the suggested detailed routing algorithm.

FAST, MINIMAL, AND OBLIVIOUS ROUTING ALGORITHMS ON THE MESH WITH BOUNDED QUEUES

2001 ◽  
Vol 02 (04) ◽  
pp. 445-469 ◽  
Author(s):  
AMI LITMAN ◽  
SHIRI MORAN-SCHEIN
Keyword(s):  
Queuing Theory ◽  
Routing Algorithm ◽  
Open Loop ◽  
Routing Algorithms ◽  
Routing Problem ◽  
Loop Control ◽  
Critical Edge ◽  
Oblivious Routing ◽  
Two Stages ◽  
Permutation Routing

This paper studies fast, deterministic permutation routing algorithms with bounded queues on the n×n mesh. Our main result is an O(n)-step, strongly-dimensional (and thus also source-oblivious and minimal) permutation routing algorithm. This algorithm works under a relaxed model in which nodes can freely send data to their neighbors. In a more prevalent model, the standard model, data may be sent only when accompanied by a packet. Under this model we present the following two algorithms: an O(n log n)-step strongly-dimensional algorithm and an O(n)-step oblivious and weakly-dimensional (and thus also minimal) algorithm. As said, all these algorithms store only O(1) packets in a node. Moreover, they use only O( log n) state bits in a node and transfer only O( log n) data bits on an edge in a step. All our routing algorithms are based on the following new technique of open-loop flow control. An algorithm is composed of two stages: setup and transportation. The setup stage computes certain values and stores them in the network. In particular, it computes a rational number α(e) for certain critical edges e. The transportation stage moves the packets to their destinations. It uses the computed values to slow the packets so that the traffic on each critical edge e is bounded byα(e); that is, at most ⌈α(e) · l⌉ packets traverse e during any l consecutive steps. This bounded on the burstiness of the traffic enables the algorithm to avoid hot spots and maintain bounded queues. The algorithm achieves this by an open-loop control; that is, during this stage no information is transferred in a direction opposite to that of the packets. An additional novelty of our algorithms is the application of a dynamic routing problem to solve a static one. The dynamic problem in question seems easy, as its networks is just a linear array. We show, however, that this problem is beyond the scope of the Adversarial Queuing Theory.

Inter-domain routing in integrated LTE and WLAN networks

2021 ◽  
pp. 506-517
Author(s):  
Shashank Tripathi ◽  
Mrinal Ranjan ◽  
Ravi Shankar ◽  
Ramesh Kumar Meena
Keyword(s):  
Routing Protocol ◽  
Rural Areas ◽  
Routing Algorithms ◽  
Network Simulator ◽  
Integrated Network ◽  
Internet Service ◽  
Integrated Networks ◽  
Research Article ◽  
Selection Of ◽  
Inter Domain Routing

The integrated LTE and WLAN Networks provide flexibility to use the Internet in Rural areas of India where their network infrastructure is not available. The research article focus to provide Internet service to the rural area end-users with a certain level of defined QoS as per ITU and TRAI guidelines. The selection of the best-suited routing protocol may have the capacity to help to achieve our objective. In the integrated network, it is much common to use a diverse variety of inter-domain routing protocol for forwarding packets by routing table updates. These tables are part of the memory of routers that help to forward packets from source to destination using their routing algorithms so that more users may experience QoS. This paper evaluates the performance of Bellman BGPv4, Inter OSPFv2, and Inter RIPv2 in terms of Routing Overhead for the integrated networks under a virtual QualNet 9.1 network simulator scenario.

scholarly journals An Optimum Channel Routing Algorithm in the Knock-knee Diagonal Model

VLSI Design ◽  
1994 ◽  
Vol 1 (3) ◽  
pp. 233-242 ◽  
Author(s):  
Xiaoyu Song
Keyword(s):  
Routing Algorithm ◽  
Difficult Problem ◽  
Layout Design ◽  
Channel Routing ◽  
Routing Problem ◽  
Vlsi Layout ◽  
Channel Density ◽  
Optimum Algorithm ◽  
Important Time ◽  
Optimum Channel

Channel routing problem is an important, time consuming and difficult problem in VLSI layout design. In this paper, we consider the two-terminal channel routing problem in a new routing model, called knock-knee diagonal model, where the grid consists of right and left tracks displayed at +45° and –45°. An optimum algorithm is presented, which obtains d + 1 as an upper bound to the channel width, where d is the channel density.

PERMUTATION ROUTING AND SORTING ON THE RECONFIGURABLE MESH

1998 ◽  
Vol 09 (02) ◽  
pp. 199-211
Author(s):  
SANGUTHEVAR RAJASEKARAN ◽  
THEODORE MCKENDALL
Keyword(s):  
Lower Bound ◽  
Randomized Algorithms ◽  
Linear Array ◽  
Order Term ◽  
Routing Algorithm ◽  
Sorting Algorithm ◽  
Routing Problem ◽  
Reconfigurable Mesh ◽  
Permutation Routing ◽  
Time Bounds

In this paper we demonstrate the power of reconfiguration by presenting efficient randomized algorithms for both packet routing and sorting on a reconfigurable mesh connected computer. The run times of these algorithms are better than the best achievable time bounds on a conventional mesh. Many variations of the reconfigurable mesh can be found in the literature. We define yet another variation which we call as Mr. We also make use of the standard PARBUS model. We show that permutation routing problem can be solved on a linear array Mr of size n in [Formula: see text] steps, whereas n-1 is the best possible run time without reconfiguration. A trivial lower bound for routing on Mr will be [Formula: see text]. On the PARBUS linear array, n is a lower bound and hence any standard n-step routing algorithm will be optimal. We also show that permutation routing on an n×n reconfigurable mesh Mr can be done in time n+o(n) using a randomized algorithm or in time 1.25n+o(n) deterministically. In contrast, 2n-2 is the diameter of a conventional mesh and hence routing and sorting will need at least 2n-2 steps on a conventional mesh. A lower bound of [Formula: see text] is in effect for routing on the 2D mesh Mr as well. On the other hand, n is a lower bound for routing on the PARBUS and our algorithms have the same time bounds on the PARBUS as well. Thus our randomized routing algorithm is optimal upto a lower order term. In addition we show that the problem of sorting can be solved in randomized time n+o(n) on Mr as well as on PARBUS. Clearly, this sorting algorithm will be optimal on the PARBUS model. The time bounds of our randomized algorithms hold with high probability.

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