As the wireless sensor network WSN technology evolves towards higher transmission rates, it makes sense to start considering sensing and transmission of real-time information, such as audio and video. These applications require quality of service QoS guarantees, not offered by current networks. In addition, researchers have recently realized that cross-layer protocols achieve a far better performance than protocol layers working in isolation. These two ingredients are the focus of our work. In this paper we propose an architecture in which the MAC and routing protocols collaborate to discover and reserve routes, to organize nodes into clusters and to schedule the access to the transmission medium in a coordinated time-shared fashion.
As a consequence, not only QoS is achieved but also great energy savings by eliminating collisions and considerably reducing idle listening.
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Multipath routing, which consists of giving a node the. Re ference  proposes for the sin k to.
This is a good m ethod for service. The authors of  propose an adaptive. When this message reaches the desired destination through. These messages mark the nodes v isited according to the. Then, neighboring nodes share their quality marks.
There is a scalability pro blem in this. In addition, similar to what was mentioned in. In , on the. Other papers propose the introduction of priorities as a way. Establishing priorities for different types of traffic is. Another alternative is the use of congestion control. Acting impl ies. In the former case,. In the. Our approach is based on res erving from the very. The different protocol componen ts include appropriate. Route discovery and weight as signment. The first steps of our proposed protocol are the di scovery.
This procedure is.
QUATTRO: QoS-Capable Cross-Layer MAC Protocol for Wireless Sensor Networks - Semantic Scholar
Briefly e xplained, the algorit hm works. Each node, when. This continues until every node in the network. The second phase of the relevan t routing protocol consists. Wh en the second phase. In our cas e, the cost. In phase three, each sensing node will se nd a WPRB. When a. Finally, in pha se four the sin k will send bac k WRSP prob e.
When a sensing node receives one of these. If the value already stored in the load bottleneck field.
QUATTRO: QoS-capable cross-layer MAC protocol for wireless sensor networks
Similarly, if the value stored in the energy. The message will eventually. When all. Route selection and reservat ion. The second step is the reservation of resources over on e of. Every sensing node will become a traffic. Routes are. When a link reservation. The cluster will grow as more nodes. As we can see, in this proposal a clu ster is defined as a. The cluster ID will be the. There m ay be traffic flowing. Notice that a node that. Before the actual reservation process begins, the sink will. RSINT message to the sink. RSINT messag es contain the. When a node dif ferent from the sink and its one-hop.
On expiry, the node will randomly select. The previous selection will exclude those routes. The goal here is to avoid cyclic routes. If a node receives one or more intention messages, which. When that. We argue that guaranteeing a certain amount of bandwidth. The following set of control m essages should be included. The RSRQ message can be used, as mentioned above, to set. Likewise, the RSRP message.
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Lastly, the. RSACK message can be used by the node that made the. Notice that not only the intended receiver of a RSRQ message. If a reservation fails, the requesting. All of these messages. In addition to listening to these messages to keep track of. Collection of cluster interference informatio n. Information relative to the potential interference among. To do that , at the end of the route. Nodes that are not cluster heads, which will be referred to. If, on the other. B field will be. In other wo rds, req. B is the.
Each array element will contain the cluster ID, its. Assignment of activity windows to the clusters. At the end of the process described in the previous section,. The assignment of. It is important to m ention. Activity windows will repeat periodically, giving the. The time interval that includes one activity. Depending on the availability of. The setup phase. One or more non-interfering.
The algorithm places the activity. This is the reas on why. QoS metrics throughput, delay, jitter, and losses d ue to buffer. The process to assign activity windows to the clusters st arts. It will then create a two-dimensional structure called. To achieve this, the sink. If there are no columns in. If, on the other hand, there is already at. Let us first calculate the activit y. T is the duration of each cycle. T should be small enough so that the maximum delay. We can now calculate.
Fi g ure 2. C y cle structu re. S is the set of clusters to be scheduled within the i -th. Window sizes should be increased by a small. When the sink has finished these calculations, it has to. To that end, the sink will. The leaf nodes will acknowledge receipt of the AWLN. A cluster head will. This process. The system is now ready to start working in a QoS-aw are,. To make that stage start, the. The duty cycle is included so that nodes can know what.
Up to this point, communication am ong nodes occurs using. IEEE If IEEE Normal operation phase. During the normal operation phase, the only active n odes. Access to the channel is not. The polls m ay allow the. In our simulations we assume that only one. A node that receives a poll will respond with a Data frame.
If the node does no t have infor mation to. Either way, the cluster. The member node can go to sleep at this time to. If all the member nodes go to sleep before. This approach is designed to save energy by avoiding. If a node fails repeatedly to respond to polls, an error.
QUATTRO: QoS-Capable Cross-Layer MAC Protocol for Wireless Sensor Networks
Being a cluster head can be energy consuming because. That is why. The redistribution of. A and. If there is only one sink in th e system, the redistribution. Hence, having several sinks. To avoid stopping. Roshini , H. View 10 Excerpts. Method Support. Highly Influenced. View 1 Excerpt. QoS group based optimal retransmission medium access protocol for wireless sensor networks M. QoS-aware MAC protocols for wireless sensor networks: A survey M.
Quality of Service in Wireless Sensor Networks: View 2 Excerpts. References Publications referenced by this paper.