CN103731438B - For WSN based on range searching and the content transmission method of latency sensitive - Google Patents

Abstract

The present invention proposes a content transmission method based on area search and delay sensitivity for WSN, which includes the following steps: the source node sends a request message to the surrounding nodes; when the node receives the request message, it judges whether it is a content storage , and start a timer; if the node is a content storage, it is judged whether it has the content corresponding to the request message; if so, it is judged whether the content satisfies the request message completely; if all are satisfied, the node feeds back the confirmation character to the source node , otherwise, the node feeds back the confirmation character and content boundary range information to the source node; judges whether the timer expires, if yes, the source node selects the round-trip delay from multiple nodes corresponding to the received confirmation character and content boundary range information The smallest node is the target node; the target node transmits the content corresponding to the request message to the source node. The embodiments of the present invention can efficiently transmit data information required by users.

Description

Area Search Based and Delay Sensitive Content Delivery Method for WSN

technical field

The invention relates to the technical field of wireless sensor network transmission, in particular to an area search-based and delay-sensitive content transmission method for WSN.

Background technique

The current network environment has changed from the beginning of the network, and information and content are more used for sharing and cooperation, rather than being limited to being sent from one place to another. Therefore, the simple network access method based on end-to-end addressing has gradually exposed many inadaptations. In this context, a new type of network architecture system designed on the principle of "convenient access to content" - the content-centric network came into being.

A major design goal of Content-Centric Networking is to better support today's primary application: content access. Because users only care about the content and information they need, and it doesn't matter what ISP (Internet Service Provider) and ICP (Internet Content Provider) do for its storage location and transmission method. This goal determines that the architecture of the content-centric network will not be a conversational model, but should be an information-centric model, and take resource-sharing communication into account. However, all communication methods follow certain norms and standards. Therefore, it is urgent to design an efficient and flexible content-based routing and transmission technology.

At present, many researchers at home and abroad have proposed corresponding improvement methods. These methods can be roughly divided into two categories: one class advocates designing a new network architecture, directly abandoning or retaining a small part of the existing network architecture technology, but this is It is a difficult and huge system project, and various trends of thought spring up, and the whole process is relatively slow; the other type hopes to continue to maintain the existing system structure, and make continuous improvement and perfection on this basis, so that The entire huge network is gradually developing towards an increasingly mature and stable direction.

Contents of the invention

The present invention aims to solve at least one of the above-mentioned technical problems.

Therefore, the object of the present invention is to propose a method for WSN-based content transmission based on area search and delay sensitivity, which can efficiently transmit data information required by users.

In order to achieve the above object, an embodiment of the present invention proposes a content transmission method based on area search and delay sensitivity for WSN, which includes the following steps: the source node sends a request message to its surrounding nodes, and in the request A counter K is set in the message, wherein K is an integer greater than 0; when the node receives the request message, it judges whether it is a content storage, if not, when the K is not 0, forward The request message is sent to the next hop, and the K is subtracted by one. When the K is 0, the request message is no longer forwarded, and a timer is started; if the node is the content storage, then The node searches and judges whether it has the content corresponding to the request message; if the node has the content corresponding to the request message, then further judges whether the content satisfies the request message; if the content All satisfy the request message, then the node feeds back a confirmation character to the source node, otherwise, the node feeds back a confirmation character and content boundary range information to the source node; judges whether the timer expires, and if When the timer expires, the source node selects the node with the smallest round-trip delay from the multiple nodes corresponding to the received confirmation character and content boundary range information as the target node; the target node sends a message to the source The node transmits the content corresponding to the request message.

In addition, the method for WSN-based area search and delay-sensitive content transmission according to the above-mentioned embodiments of the present invention may also have the following additional technical features:

In some examples, the method further includes: discarding the request message if the node determines that it is not a content storage and the K is 0.

In some examples, the method further includes: if the node is the content storage and does not store the content corresponding to the request message, then the node discards the request message.

In some examples, the content boundary range includes: content type, interval value and time stamp.

To sum up, according to the embodiment of the present invention, the content transmission method based on area search and delay sensitivity for WSN combines the distribution characteristics of content storage in the network, and selects the content storage with the smallest round-trip delay for users to transmit their needs. The content can efficiently transmit the data information that users need.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

FIG. 1 is a flow chart of an area search-based and delay-sensitive content transmission method for a WSN according to an embodiment of the present invention; and

Fig. 2 is a schematic diagram of node distribution for a WSN-based area search and delay-sensitive content transmission method according to an embodiment of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner" and "outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and Simplified descriptions, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The area search-based and delay-sensitive content transmission method for WSN according to the embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a flow chart of a method for WSN-based area search and delay-sensitive content transmission according to an embodiment of the present invention. As shown in Figure 1, the method for content transmission based on area search and delay sensitivity for WSN according to an embodiment of the present invention includes the following steps:

Step S101, the source node sends a request message to its surrounding nodes, and sets a counter K in the request message, where K is an integer greater than 0.

Specifically, in WSN, when a certain node (source node) requests a certain content, it is not clear which content storage stores the content it needs, so after the source node joins the network, a certain range around it ( The nodes within K hops) send a request message, and set a counter K in the request message, K is an integer greater than 0.

In a specific example, as shown in FIG. 2, in FIG. 2, there are many nodes distributed around the source node, wherein node 01, node 02, node 04, node 05, node 06 and node 09 are all content storage, and the remaining nodes are common nodes.

Step S102, when the node receives the request message, judge whether it is a content storage, if not, when K is not 0, forward the request message to the next hop, and subtract one from K, when K is 0, The request message is no longer forwarded and a timer is started.

Specifically, when a node receives a request message, it first judges whether it is a content storage. If it is not a content storage, that is, if the node is a normal node, then when K is not 0, the normal node will The received request message is directly forwarded to the next hop, and K is reduced by one. Further, when K decreases to 0, the above request message is no longer forwarded, and a timer is started at this time.

Further, in the above step S102, if the above node judges that it is not a content storage and K is 0, then discard the request message.

Step S103, if the above-mentioned node is a content storage, the node searches and judges whether it stores the content corresponding to the request message. In an embodiment of the present invention, if the aforementioned node is a content storage and does not store the content corresponding to the request message, the node discards the request message.

In other words, when the node in the above step S102 judges that it is a content storage, the node further judges whether it has the content corresponding to the request message sent by the source node, and if so, executes step S104; otherwise, discards the content request message.

Step S104, if the above-mentioned node has the content corresponding to the request message, it is further judged whether the content satisfies the request message completely. That is, if the above-mentioned node (content storage) stores the content corresponding to the request message, it is further judged whether the content is exactly the same as the content corresponding to the request message.

Step S105, if all the above contents satisfy the request message, the node feeds back a confirmation character to the source node; otherwise, the node feeds back the confirmation character and content boundary range information to the source node. Wherein, in an embodiment of the present invention, the content boundary range is a multi-attribute value, for example including: content type, interval value and time stamp. As a specific example, if the content boundary range sent by a node is: temperature/[4, 28]/[2013.06.01, 2013.10.01], that is, the content type is temperature, and the range of temperature is 4-28°C , the time stamp is from June 01, 2013 to October 01, 2013.

In other words, if the content stored in the above node (content storage) is exactly the same as the content corresponding to the request message, the node (content storage) will return a confirmation character to the source node along the reverse path. If the content stored in the above-mentioned content storage does not fully satisfy (partially satisfy) the content corresponding to the request message, the content storage will reply to the source node along the reverse path to confirm the character and its stored content boundary range, specifically including: content type , interval value, and timestamp.

Step S106, judging whether the timer expires, and if the timer expires, the source node selects the node with the smallest round-trip delay from the multiple nodes corresponding to the received confirmation character and content boundary range information as the target node.

As a specific example, refer to FIG. 2 . Specifically, it is judged whether the timer in step S101 has expired. If the timer expires, the source node checks the confirmation character and content boundary range received by it, and can satisfy all or part of the content corresponding to the request message. One or more nodes (content storage) form a set, and obtain the maximum round-trip delay of each node in the set, and form the following table 1 accordingly, and finally, obtain the node with the smallest round-trip delay in table 1 (content memory) as the target node. Combined with Figure 2, Table 1 can be generated as follows:

collection of content stores Maximum round trip delay CS02, CS05, CS09 120ms CS04 180ms CS01, CS06 90ms

Table 1

Wherein, in Table 1, CS02, CS05, CS09, CS04, CS01 and CS06 are respectively node 02, node 05, node 09, node 04, node 01 and node 06 in Fig. 2, and these nodes are content storage. It can be seen from Table 1 that the round-trip delays of CS01 and CS06 are both 90 ms, which belong to the smallest round-trip delay among all the content storages in the set. Therefore, CS01 and CS02 are taken as target nodes.

Step S107, the target node transmits the content corresponding to the request message to the source node. That is, the node with the smallest round-trip delay obtained in step S106 above transmits the data content required by the user to the source node. In other words, as shown in Figure 2 and Table 1, the round-trip delay of CS01 (that is, node 01 in Figure 2) and CS06 (that is, node 06 in 2) is the smallest, then CS01 and CS06 are used as the target nodes, and the source node Transfer data content.

To sum up, the basic principle of the WSN-based area search and delay-sensitive content transmission method used in the embodiment of the present invention can be summarized as follows: the source node sends a request message to the surrounding nodes, and after the source node sends the request message, The confirmation characters of the surrounding content storage will be received successively within a period of time, and the source node will select one (or more) content storages with the smallest round-trip delay and satisfying all requested content according to the round-trip delay of each confirmation character. And establish a connection with it to transmit the requested content required by the user.

According to the content transmission method based on area search and delay sensitivity used in WSN according to the embodiment of the present invention, combined with the distribution characteristics of the content storage in the network, the content storage with the smallest round-trip delay is selected to transmit the required content for the user, which can efficiently To provide users with the data information they need.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (4)

1. A content transmission method based on area search and delay sensitive for WSN, it is characterized in that, comprises the following steps: The source node sends a request message to its surrounding nodes, and sets a counter K in the request message, where K is an integer greater than 0; After the node receives the request message, it judges whether it is a content storage, if not, when the K is not 0, forwards the request message to the next hop, and subtracts one from the K , when the K is 0, no longer forward the request message, and start a timer; If the node is the content storage, the node searches and determines whether it stores the content corresponding to the request message; If the node stores the content corresponding to the request message, further determining whether the content satisfies the request message; If the content fully satisfies the request message, the node feeds back a confirmation character to the source node along the reverse path, otherwise, the node feeds back the confirmation character and content boundary range information to the source node along the reverse path ; Judging whether the timer expires, and if the timer expires, the source node selects the node with the smallest round-trip delay from the multiple nodes corresponding to the received confirmation character and content boundary range information as target node; The target node transmits content corresponding to the request message to the source node. 2. The method according to claim 1, further comprising: If the node judges that it is not a content storage and the K is 0, the request message is discarded. 3. The method according to claim 1, further comprising: If the node is the content storage and does not store the content corresponding to the request message, the node discards the request message. 4. The method according to claim 1, wherein the content boundary range includes: content type, interval value and time stamp.