Slotless Protocols for Neighbor Discovery in Wireless Networks

用于无线网络中邻居发现的无时隙协议

• 批准号: 387044055
• 负责人: Professor Dr. Samarjit Chakraborty
• 金额: --
• 依托单位: Department of Computer Science
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387044055?language=en
• 关键词: Slotless; Protocols; Neighbor; Discovery; Wireless

Within the last decade, networks which do not require any fixed infrastructure (mobile ad-hoc networks, MANETS) have become widespread. Before two devices in a MANET can start communicating, they have to discover their mutual existance and synchronize their clocks using a procedure called neighbor discovery. Since all participants of a MANET are powered by batteries, power-efficient neighbor discovery is a crucial requirement. In such protocols, a device repeatedly broadcasts packets on a certain set of channels, whereas other devices repeatedly switch on their receivers for short amounts of time. To save energy, the devices sleep in the meantime. Two devices have discovered each other successfully once both have received a first packet from their opposite. Most common neighbor discovery protocols are referred to as slotted protocols. They subdivide time into multiple, equal-length intervals, called slots. In some slots, the device remains asleep, whereas other ones are active slots used for communication. The discovery procedure is complete once two active slots overlap in time. The pattern of active and sleep slots is defined by a specific schedule. The protocol design problem from the perspective of neighbor discovery is to identify schedules that lead to low energy consumptions, while ensuring low-latencies. In the last years, schedules of active/passive slots, which guarantee deterministic worst-case bounds on the discovery latencies have been an active field of research. In this project, we consider a different paradigm which may be characterized as slotless. In protocols following this paradigm, the transmitting device send packets at periodic intervals, with the transmission duration determined by the size of a packet. The other device switches on its receiver also at periodic intervals and remains on for a specified duration during each period. The lengths of the periodic intervals as well as the on-durations of the receiver are drawn over continuous time. Our preliminary work indicates that for almost all parametrizations of these protocols, deterministic latency bounds can be guaranteed and certain choices of interval lengths lead to significantly shorter discovery-latencies than the best known slotted protocols, while consuming the same amount of energy. The main goal of this project is to develop analytical models for slotless protocols and, based thereupon, to develop novel protocols with higher performances than all existing ones. These protocols are then implemented to verify their behavior in real-world networks.

在过去十年中，不需要任何固定基础设施的网络（移动的自组织网络，MANETS）已经变得普遍。在MANET中的两个设备可以开始通信之前，它们必须发现它们的相互存在，并使用称为邻居发现的过程来同步它们的时钟。由于MANET的所有参与者都由电池供电，因此节能的邻居发现是一个至关重要的要求。在这样的协议中，设备在特定的信道集合上重复地广播分组，而其他设备在短时间内重复地打开它们的接收器。为了节省能源，设备在此期间处于睡眠状态。一旦两个设备都从它们的对端接收到第一个分组，则两个设备成功地发现了彼此。最常见的邻居发现协议被称为时隙协议。它们将时间细分为多个等长的间隔，称为时隙。在某些插槽中，设备保持休眠状态，而其他插槽则是用于通信的活动插槽。一旦两个活动时隙在时间上重叠，发现过程就完成。活动时隙和休眠时隙的模式由特定调度定义。从邻居发现的角度来看，协议设计问题是确定导致低能耗的调度，同时确保低延迟。在过去的几年中，主动/被动时隙的时间表，保证确定性的最坏情况下的发现延迟的界限一直是一个活跃的研究领域。在这个项目中，我们考虑一个不同的范例，其特点可能是无槽。在遵循该范例的协议中，发送设备以周期性间隔发送分组，其中传输持续时间由分组的大小确定。另一个设备也以周期性的间隔打开其接收器，并在每个周期期间保持打开指定的持续时间。周期性间隔的长度以及接收器的接通持续时间是在连续时间上绘制的。我们的初步工作表明，这些协议的几乎所有参数化，确定性的延迟界限可以保证和一定的选择的间隔长度导致显着较短的发现，延迟比最知名的时隙协议，同时消耗相同的能量。该项目的主要目标是为无时隙协议开发分析模型，并在此基础上开发出比现有协议性能更高的新型协议。然后，实现这些协议，以验证它们在现实网络中的行为。