【正文】 ely. ? Node Energy Level (NEL): The current energy level of a node is called NEL. For example, at the time of broadcasting a control packet, if energy level of a node is x units, NEL is assigned as x units in the control packet. ? Parent Gateway Power Level (PGPL): The transmission power level of the parent gateway of any group with which it can be connected with the child gateway of an upstream group is known as Parent Gateway Power Level (PGPL). Since, sink is always the parent gateway in its group, its PGPL is assigned to 0. However, for the parent gateway of other groups, Pmin PGPL Pmax, which may have value between 1 and 3, as per our assumption. ? Source ID (SID): If A and B are two different sensor nodes of the same or different groups such that A sends packet to B, A is the source for B and ID of node A is the Source ID (SID). 3. The distributed power control protocol In this section we present our power control based topology construction protocol, which constructs the topology dynamically. We assume that each node in the work has a unique ID and each of them knows its onehop neighbor’s ID prior to the construction of the topology. As per the system model of our protocol, since connectivity holes exist among each group of nodes, we assume that the work may be disconnected, if they use low transmission power level between one group of nodes with another and can consume more energy, if they use maximum transmission power level for munication. Moreover, in our assumption the transmission power level for all nodes in the work after deployment could be maximum or in between minimum and maximum. So, in our protocol, a tree topology is constructed among each group of nodes using minimum transmission power level (Pmin = 0 here) and a connected tree topology of the whole work is formed among different group of nodes using an effective power level (PTx), where (Pmin=0)PTx (Pmax=3). The different phases of this distributed protocol are described as follows. . Construction phase As soon as the nodes are deployed on the work, the sink initiates the construction phase by broadcasting a construct packet with minimum transmission power (Pmin = 0) to get connected with its immediate neighbors, as shown in Fig. 4(a). The format of the construct packet is shown in Fig. 3 and the parameters of the packet are initialized as: SID = Sink’s ID, PGID = Sink’s ID, NEL = Sink’s power level, LHC = 0, GHC = 0, PGPL = 0. Since, sink node generally receives the data, its PGPL is assigned to 0, which is different for other parent gateways of the work. Upon receiving the construct packet, the neighbors of the sink within its minimum transmission power range (Pmin = 0), scan all parameters of the packet. They wait for the random time Wi, as defined in Eq. (1), and get connected with the sink. Let Ni, be the number of neighbors of ith node, out of N nodes in the work. Upon receiving a construct packet, the waiting time of the ith node can be considered as: (1) where αi is a small random number patible with CSMACA mechanism [22]. Then, each of them rebroadcasts the construct packet using the same minimum power level Pmin = 0 to their neighbors with necessary increments to the parameters of the construct packet and waits for time Ti units, as defined in Eq. (2). (2) where Ei is the current energy level of ith node and βi is a very small random number such that βi . Fig. 3. Format of the construct packet. In order to avoid the packet collision among group of nodes in a dense work, we propose that the sink also waits for Ti units after broadcasting the construct packet and then goes to the information phase, as described in Section . It is to be noted that sink must be within at least one of the sensor node’s minimum or maximum transmission power range. However, if the sink does not find any neighbor with Pmin = 0, it goes to the information phase to construct the link with its neighbors, after the waiting time Ti has elapsed (Table 2 and Table 3). Table 2. Construction phase algorithm for the sink and any node of the work ALGORITHM 1: Construction Phase For the Sink: 1. Initialize: Parameters and Local Hop Count (LHC)=0。 6. Set: Pmin=0。 5. Initialize: All parameters of the Inform packet。 7. Copy value of GHC from the Inform packet to the respective field of the Construct packet。 5. Estimate effective transmission power (PTx(ij)) between the closest sender and itself。 13. Go to Maintenance Phase, as described in Section (C). Table 3. Information phase algorithm for both Sender and Receiver ALGORITHM 2: Information Phase For any Sender(i): 1. If: (Receives Construct packet) 2. { 3. Copy value of PGID and GHC from the Construct packet。 4. Scan LHC of each received packets。 177。 數(shù)據(jù)包的 PGPL 字段中給出的上游組可連接節(jié)點的有效功率級別。 (6) 應注意一個組的節(jié)點可能是另一個節(jié)點的已收到幾個通知數(shù)據(jù)包。此外，從每個發(fā)送方使用下面的公式估計其物理距離。 它通過廣播通知數(shù)據(jù)包使用最大傳輸功率級 (Pmax = 3)。 接收機節(jié)點等待無線設(shè)備、連接的源和上文所述，然后按照相同的步驟。 8.} : 進入維護階段 , 在 (C)節(jié)中描述 。 Ti 個單位 。 4. 等待 Ti 個單位 。 他們等待隨機時間 Wi，并與接收器連接。 在本節(jié)中，我們將提出我們基于拓撲結(jié)構(gòu)協(xié)議的功率控制，這是一種動態(tài)的拓撲結(jié)構(gòu)。在某些的情況下如果一組都包含唯一的節(jié)點的單個節(jié)點被視為為該組的父和子網(wǎng)關(guān)。 數(shù)學上，讓 G = {g1， g2 … …， gn}，作為組中的 n 傳感器節(jié)點集， m 傳感器節(jié)點的組處于相同或不同的 m 和 n 的值的另一個組。同樣，如果控制數(shù)據(jù)包 G2 從廣播到這些組，在這種情況下 G G4 被視為下游組的 G2， G2 可以組 G G4，一個上游組。 圖 之間的不同的組節(jié)點 表 1 對于不同的電力能源消費水平和相應的交流 ,得到了來自我們距離的實驗結(jié)果 功率電平 0 1 2 3 輸出功率 (dBm) ?13 ?7 ?1 5 范圍 (m) 177。性能分析和仿真結(jié)果在第 4 節(jié)而結(jié)論 在第 5節(jié)。另外 ,而非控制發(fā)射功率水平 ,總是使用一個固定的高功率水平網(wǎng)絡(luò)的節(jié)點的節(jié)點將迅速減少死亡網(wǎng)絡(luò)的生存時間。畢竟 ,部件連接環(huán)和優(yōu)化的后處理解除功耗的網(wǎng)絡(luò)。在[16]中 ,兩個局部拓撲結(jié)構(gòu)的控制算法 ,并提出了異構(gòu)多跳無線網(wǎng)絡(luò)的非均勻傳輸范圍。分析是在非對稱無線鏈接并不罕見，具有不同的最大傳輸范圍，在異構(gòu)無線設(shè)備的網(wǎng)絡(luò)拓撲控制的問題。定期報告中 ,節(jié)點模型的數(shù)據(jù)收集和可聚合所需資料 ,成為集 ,然后 定期的發(fā)送到 上游。 關(guān)鍵詞：無線網(wǎng)絡(luò)傳感器，分布式算法，功率控制，拓撲結(jié)構(gòu) 近年來在硬件和軟件的無線網(wǎng)絡(luò)技術(shù)的發(fā)展 ,使小尺寸、低功耗、低成本、多功能傳感器節(jié)點 [1]的基礎(chǔ)上 ,由傳感、數(shù)據(jù)處理及無線通信組件 組成 。由于傳感器能量資源的有限 ,他們中的每一個都應該減少能源消耗 ,延長網(wǎng)絡(luò)的生命周期。除此之外 ,補充能量的電池更換和充電幾