Previous research in wireless ad hoc networks typically assumes the use of omnidirectional antennas at all nodes. With antennas, while two nodes are communicating using a given channel, MAC protocols such as IEEE 802.11 require other vicinity to stay silent. directional pairs located each other's may potentially communicate simultaneously, depending on directions transmission. This can increase spatial reuse channel. In addition, higher gain allows node with far away, implying that messages...

This paper proposes a vehicle-to-vehicle communication protocol for cooperative collision warning. Emerging wireless technologies (V2V) and vehicle-to-roadside (V2R) communications such as DSRC are promising to dramatically reduce the number of fatal roadway accidents by providing early warnings. One major technical challenge addressed in this is achieve low-latency delivering emergency warnings various road situations. Based on careful analysis application requirements, we design an...

The aggregate throughput of a wireless ad hoc network depends on the channel capacity, utilization (i.e., fraction capacity used for generating good put), and concurrent transmissions allowed in network. While is determined by MAC overhead, physical carrier sense has been as an effective way to avoid interference exploit spatial reuse. Prior research attempted identify optimal range that can maximize throughput. However, impact overhead ignored. In this paper, we use both analytical model...

Energy saving is a critical task for sensor networks with limited energy supply. Wakeup schemes that turn off sensors' radio when communication not necessary have great potential in saving. However, existing wakeup encounter tradeoffs between and latency, little attention has been paid to reducing the packet end-to-end delay while preserving capability. We argue long can be detrimental large networks. propose scheme helps achieve balance delay. The conditions under which proposed show...

Ad hoc networks formed without the aid of any established infrastructure are typically multi-hop networks. Location dependent contention and "hidden terminal" problem make priority scheduling in significantly different from that wireless LANs. Most prior work related to addresses issues In this paper, is discussed. We propose a scheme using two narrow-band busy tone signals ensure medium access for high source stations. The simulation results demonstrate effectiveness proposed scheme.

In this paper, we study the emerging heterogeneous multi-radio network, focusing on interference issues due to simultaneous operation of multiple radios. A comprehensive review is given sources coexistence interference, including transmitter noise, receiver blocking, and inter-modulation. We compare various techniques, relevant standardization efforts. Then, propose a media independent service (MICE) layer, suggest that performance system can be further improved if necessary support...

As virtualization trend is moving towards "client virtualization", wireless remains to be one of the technology gaps that haven't been addressed satisfactorily. Today's approaches are mainly developed for wired network, and not suitable virtualizing network interface due fundamental differences between LAN devices we will elaborate in this paper. We propose a approach named virtual WiFi addresses gap. With our proposed solution, full functionalities supported inside machines; each machine...

In recent years, Wireless Local Area Networks (WLAN) have become the premier choice for many homes and enterprises. WiMAX (Worldwide Interoperability Microwave Access) has also emerged as wireless standard that aims to deliver data over long distances, can potentially provide broadband access an alternative wired cable DSL networks. Parallel with surge of networks is explosive growth multimedia applications. Therefore, it important explore efficient methods delivering in such settings. this...

Dynamic spectrum access networks are designed to allow today's bandwidth hungry "secondary devices" share allocated legacy devices, or "primary users." The success of this wireless communication model relies on the availability unused spectrum, and ability secondary devices utilize without disrupting transmissions primary users. While recent measurement studies have shown that there is sufficient underutilized available, little known about whether can efficiently make use available while...

Relay is one of the key features being considered for IMT-Advanced systems. The relay architectures defined in IEEE 802.16m and 3GPP LTE-Advanced are optimized only non-mobile relay, i.e., Station attached to a designated Base becomes part fixed access network. A mobile architecture, where may switch BS according operation demand, will promise more resilient deployment. In this paper, we first highlight three use cases relays can offer useful deployment options. Next, propose an enhanced...

Traditional medium access control (MAC) protocols utilize temporal mechanisms such as probability or backoff interval adaptation for contention resolution. Temporal resolution aims to separate transmissions from different nodes in time achieve successful transmissions. We explore an alternative approach wireless networks - named "spatial that adapts the "space" occupied by By adapting space transmissions, set of "locally" competing nodes, and thus, channel level, can be adjusted reach a...

As virtualization trend is moving towards "client virtualization", wireless remains to be one of the technology gaps that haven't been addressed satisfactorily. Today's approaches are mainly developed for wired network, and not suitable virtualizing network interface due fundamental differences between LAN devices we will elaborate in this paper. We propose a approach named virtual WiFi addresses gap. With our proposed solution, full functionalities supported inside machines; each machine...

Dynamic spectrum access networks are designed to allow today's bandwidth-hungry “secondary devices” share allocated legacy devices, or “primary users.” The success of this wireless communication model relies on the availability unused and ability secondary devices utilize without disrupting transmissions primary users. While recent measurement studies have shown that there is sufficient underutilized available, little known about whether can efficiently make use available while minimizing...

We formulate the problem of network-coding (NC)-based scheduling for media transmission to multiple users over a wireless-local-area-network-like or WiMAX-like network as Markov decision process (MDP). NC is used minimize packet losses that resulted from unreliable wireless channel conditions, whereas MDP employed find optimal policy transmissions unequally important packets. Based on this, dynamic programming technique give an policy. However, this quickly leads computational...

Traditional medium access control (MAC) protocols utilize temporal mechanisms such as probability or backoff interval adaptation for contention resolution. They typically take the set of competing nodes a given, and address problem adapting each node's channel behavior to given level. This is approach resolution, which aims separate transmissions from different in time achieve successful transmissions. We explore an alternative wireless networks-named "spatial backoff-that adapts "space"...

We consider data-streaming from an access point to multiple receivers, which is modeled as packet erasure channel. A simple network coding shown achieve larger rate region than without coding, using minimal control information. The performance characterized exactly state transition graph. scheme then mapped information theoretic formulation for broadcast channel with feedback. It exhibits a much simpler example showing feedback improves the capacity region, compared Ozarow's 1984...

Wireless mesh networks have attracted increasing attention and deployment as a high-performance low-cost solution to last-mile broadband Internet access. Traffic routing plays critical role in determining the performance of wireless network. To investigate best solution, existing work assumes traffic demand is static known priori. However, recent studies network traces show that demand, highly dynamic hard estimate. This paper an oblivious algorithm able provide optimal worst-case on all...

LiDAR-Camera fusion can effectively provide the complementary geometric and appearance information for 3D object detection task of autonomous driving system. However, current dominant methods designed urban scenes often fuse multi-modal into a Bird's-Eye-View (BEV) feature representation have relatively short perception range, which limits their application in surface mine. To achieve long-range mine, we utilize solid-state LiDAR (i.e. Livox Horizon) that has large range (over 200 meters)....

To reduce medium access control (MAC) overhead and improve channel utilization, there has been extensive research on dynamically adjusting the behavior of a contending station based feedback information. This paper explores an alternative approach, named pipelined packet scheduling, to MAC overhead. overheads can be divided into bandwidth-dependent bandwidth-independent components these both reduced by using split-channel pipelining mechanisms, as demonstrated in this paper. In past,...

In this paper, we study a multi-radio network, where at least one station has multi-standard transceivers operated simultaneously. A radio the device can suffer service disruptions due to interference from collocated radios or constraints shared resources. impact of temporal disruption on fairness for CSMA-. based such as WLAN. We propose novel credit payback (CP) mechanism mitigate disruptions. Credits are saved during and used compensate lost transmission opportunities disruptive stations....