Flooding Location Based AHBP SBA DCB in .NET framework

Making QR Code 2d barcode in .NET framework Flooding Location Based AHBP SBA DCB
Flooding Location Based AHBP SBA DCB
QR Code ISO/IEC18004 Scanner In .NET
Using Barcode Control SDK for VS .NET Control to generate, create, read, scan barcode image in VS .NET applications.
Overhead
Making QR Code In VS .NET
Using Barcode creator for Visual Studio .NET Control to generate, create QR Code image in .NET framework applications.
Drop Probability
QR Code Recognizer In Visual Studio .NET
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET framework applications.
Figure 3.17. Overhead (PRW, controlled drop, 30 nodes).
Create Bar Code In .NET
Using Barcode maker for VS .NET Control to generate, create barcode image in .NET applications.
CHARACTERIZING NWB UNRELIABILITY
Scan Bar Code In .NET
Using Barcode decoder for .NET Control to read, scan read, scan image in VS .NET applications.
0.8 Coverage
Create QR In C#
Using Barcode creator for .NET framework Control to generate, create QR image in VS .NET applications.
Flooding Location Based AHBP SBA DCB
Paint QR In Visual Studio .NET
Using Barcode generator for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
Drop Probability
QR Code Encoder In Visual Basic .NET
Using Barcode printer for .NET Control to generate, create Denso QR Bar Code image in .NET applications.
Figure 3.18. Coverage (PRW, controlled drop, 60 nodes).
Draw Barcode In .NET
Using Barcode maker for Visual Studio .NET Control to generate, create barcode image in Visual Studio .NET applications.
As one would expect, the coverage obtained for a 60-node environment is higher than that of the 30-node environment, as can be seen when contrasting Figures 3.18 and 3.16. 3.5.7 Notes The experiments presented in this section show that in sparse environments and environments under high load, the level of redundancy present in the NWB protocols is often not enough (see Figure 3.19). The protocols cannot adapt to losses and therefore are not robust. This weakness needs to be understood and addressed, which we will do in the next sections.
Generate Barcode In Visual Studio .NET
Using Barcode printer for VS .NET Control to generate, create barcode image in .NET applications.
1.2 1 0.8 0.6 0.4 0.2 0
Data Matrix 2d Barcode Creation In .NET
Using Barcode creator for .NET framework Control to generate, create Data Matrix image in Visual Studio .NET applications.
Flooding Location Based AHBP SBA DCB
Drawing Bookland EAN In Visual Studio .NET
Using Barcode maker for .NET framework Control to generate, create International Standard Book Number image in .NET framework applications.
Overhead
Bar Code Reader In .NET Framework
Using Barcode reader for VS .NET Control to read, scan read, scan image in VS .NET applications.
Drop Probability
DataMatrix Creator In Visual Basic .NET
Using Barcode maker for VS .NET Control to generate, create ECC200 image in .NET framework applications.
Figure 3.19. Overhead (PRW, controlled drop, 60 nodes).
ANSI/AIM Code 39 Maker In Visual Studio .NET
Using Barcode generation for ASP.NET Control to generate, create Code 39 Extended image in ASP.NET applications.
ROBUSTNESS CONTROL FOR NETWORK-WIDE BROADCAST
Making UPCA In Java
Using Barcode generator for Java Control to generate, create Universal Product Code version A image in Java applications.
3.6 ROBUSTNESS CONTROL SOLUTION SPACE Increasing NWB reliability requires increasing the probability of the reception of the NWB rebroadcast operations. This is especially true in situations where their loss is likely and the redundancy in the network is low. The goal of the solutions presented in this chapter is to improve the reliability of the NWB, rather than ensure complete reliability; guaranteed reliability requires too much overhead (for example, neighbor discovery and the use of unicast packets). With solutions for robustness control, NWB algorithms can now be thought of in two parts: (1) redundancy control: this phase of the algorithm targets reducing the redundancy in the rebroadcasts; and (2) robustness control: this phase of the algorithm attempts to recover from losses occurring in the transmissions necessary to cover the nodes. The focus of most existing solutions is redundancy control; in contrast, our focus here is on robustness control. There are several possible approaches for redundancy control which are classi ed in the remainder of this section. Please note that even though robustness control is discussed separately from the remainder of the NWB and redundancy control aspects of the algorithm, often the most appropriate choice is in uenced by the structure of the underlying algorithm. Examples of such inter-dependence will be discussed as different points in the solution space are examined in more detail in the following three chapters. Approaches to robustness control can be classi ed along multiple axes, including the following. First, we distinguish solutions according to how they trigger robustness control responses (typically additional rebroadcasts). Fixed redundancy approaches incorporate a xed degree of redundancy in their coverage, beyond the minimum necessary, to leave a safety margin against broadcast losses. In contrast, loss sensitive approaches, trigger additional redundancy (typically in the form of additional rebroadcasts) only when losses are detected or predicted. Among loss-sensitive approaches, there is a number of solutions possible based on the approaches for detecting/predicting losses and how redundancy is built in response. Broadly, losses detection/prediction can be accomplished by explicit or implicit feedback. 3.6.1 Explicit Feedback Algorithms In explicit feedback algorithms, the receivers inform the senders of whether the broadcast was received successfully using an explicit transmission. Explicit feedback solutions face the following problem: If multiple receivers of a MAC broadcast have to provide acknowledgements, collisions occur. However, its possible to randomize/stagger the responses or require feedback from a subset of the receivers only. With explicit feedback, the granularity of the feedback can be adjusted. The simplest scheme is to provide feedback on every NWB transmission. This has the cost of immediate latency in a NWB operation. Another approach that can be used to provide feedback about NWB successes is to inform the sending node periodically. This requires nodes to cache previously sent data, in case a failure situation arises.
Encode Data Matrix ECC200 In C#.NET
Using Barcode generation for .NET framework Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
ROBUSTNESS CONTROL SOLUTION SPACE
Code128 Creator In Visual Basic .NET
Using Barcode encoder for .NET Control to generate, create Code 128B image in Visual Studio .NET applications.
Depending on the granularity and the subset of receivers responding, explicit feedback may also increase latency and load on the network (due to the acknowledgment traf c). 3.6.2 Implicit Feedback Algorithms Schemes that use implicit feedback attempt to judge the success of a NWB transmission based on locally observed behavior and without requiring addition control packets to be exchanged. Brie y, this approach hypothesizes that the behavior of the neighbors in the case where they receive a broadcast will be different from their behavior in the case where they don t. Thus, by observing the behavior of nearby nodes, the loss probability can be predicted. A simple example of such implicit feedback is for a node to observe the channel and see if the NWB packet was retransmitted by neighboring nodes. If enough retransmissions are overhead, it is likely that the original transmission to the neighbor was received successfully. Implicit feedback solutions can improve their decision by factoring in other criteria that can improve the loss prediction. For example, each node can measure the utilization of the channel; the higher the utilization, the higher the probability of a loss. However, this approach is imprecise because the local state at the sender may not match that at the receivers. An additional metric of interest is the expected number of rebroadcasts (a function of density and NWB algorithms), the knowledge of which can help re ne the prediction made by the implicit feedback mechanism. An interesting hybrid approach uses explicit feedback to estimate the probability of success of a broadcast and perhaps the criticality of it; this approach is termed stateaware. This approach is similar to the utilization and density estimation discussed above. However, because those estimates are created based on the imprecise source view, they may not be valid at the destination where losses occur. Furthermore, link utilization is only one of the factors that in uence the quality of the wireless channel; other factors cannot be assessed without feedback from the receiver [32]. State-awareness can be combined with implicit feedback or xed redundancy algorithms. Most NWB solutions view the link quality as boolean: Links either exist or they do not. The quality of links differs due to many variables, including the distance between the nodes, the power of transmissions between the nodes, and the overall traf c nearby [32]. NWB solutions can leverage this data in order to provide NWB robustness for example, by building in more redundancy for nodes that are covered only by weak transmissions in a xed redundancy NWB algorithm. 3.6.3 Classifying Existing Solutions Full reliability for NWBs is an expensive operation. Using the 802.11 Medium Access Control (MAC) layer, the only mechanism for a reliable transmission is with unicast packets, which have an optional Request To Send/Clear To Send (RTS/CTS) handshake, followed by the data transmission, followed by an acknowledgment (ACK) packet. If the ACK is not received by the sending node, the process is retried, up to 7 times.
Bar Code Maker In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create barcode image in ASP.NET applications.
Make Barcode In VB.NET
Using Barcode generator for VS .NET Control to generate, create barcode image in .NET framework applications.