在以無線電(radio)為基礎的無線網路中，當一個節點試圖廣播訊息給其他節點時會容易產生廣播風暴(broadcast storm)。在一倍無線電涵蓋範圍內所有的節點(1-hop neighbor)會以重播(rebroadcast)的方式來轉播收到的訊息。因為無線電訊號即是廣播，因此重播的訊號間容易互相干擾而造成訊號的碰撞或遺失，這樣的問題在需要相當密集分佈的無線感測器網路(wireless sensor networks)中尤其嚴重。
不幸的是，現有的大多數研究中都假設無線電涵蓋範圍是極度理想的穩定且形狀是圓形。然而在現實的狀況裡，無線電訊號的涵蓋範圍卻是極度動態且不規則的。在這篇論文中，我們考慮了高密度且訊號涵蓋範圍不規則的無線感測器網路。主要想法是先根據訊號強度選擇出那些在訊號涵蓋範圍邊緣的節點當作邊緣鄰居(rim neighbor)。接著再從這些邊緣鄰居中選擇傳播者(forwarder)來涵蓋兩倍無線電涵蓋範圍內所有的節點(2-hop neighbor)。不同於以往的研究，我們提出的方法－RIM不需要維護鄰居的資訊，因為在訊號涵蓋範圍不規則的狀況下鄰居資訊是動態的並且在高密度的分佈情形下維護鄰居資訊所造成的負擔也相當高。透過實驗模擬，我們比較RIM與DCB　[10]，結果顯示在高密度且訊號涵蓋範圍不規則的狀況下，RIM的效能表現會比DCB好。

Broadcast storm occurs in radio-based wireless networks when a node attempts to broadcast a message to other nodes. All the 1-hop neighbors within the radio coverage range will relay the message by rebroadcasting it. Since radio signal is broadcast in nature, the rebroadcast communications can easily interfere with each other, causing the rebroadcast message to corrupt. The problem becomes especially serious in wireless sensor networks which often require very dense deployment.
Unfortunately, most previous solutions assumed a perfect radio condition with a fixed, circular coverage region. However, in real practice, radio signals are very dynamic and irregular in their coverage. In this study, we consider dense wireless sensor networks with irregular radio coverage. The idea is to first find the rim neighbors, the neighbors on the rim of the irregular radio coverage region, according to signal strength. The forwarder set is then selected from the rim neighbors to cover all the 2-hop neighbors. Unlike previous works, the proposed algorithm, RIM, does not maintain neighbor sets, because neighbor sets will be very dynamic under irregular radio coverage while the maintenance overhead will be very high for dense sensor networks. Through simulation, we compare the proposed RIM algorithm with Double-Covered Broadcast (DCB) [10]. The results show that under dense deployment and irregular radio coverage, our algorithm performs better than DCB.

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