[資(zi)料來源(yuan):網絡]

Building a networked control system over wireless is a challenging task. The scarce spectrum imposes a fundamental
limit on the performance of the wireless channel.Random delays and packet losses are inevitable
建(jian)立網絡(luo)化的(de)無線控制系(xi)統(tong)是一個極富(fu)挑戰性的(de)任(ren)務。頻譜(pu)資源的(de)稀缺對無線信道的(de)工(gong)作性能(neng)帶來了很大的(de)限(xian)制。隨機(ji)延滯和(he)數(shu)據包(bao)丟失是不(bu)可(ke)避(bi)免的(de)。

Even though this is true for any communication network, it
is much more pronounced in wireless networks due to limited spectrum and power, time-varying channel gains and interference.
盡管在任何通訊網絡(luo)中(zhong)(zhong)都會出現類似問題，但在無線網絡(luo)中(zhong)(zhong)，由于(yu)頻(pin)譜(pu)資源和(he)功(gong)率的限制，以及隨(sui)時間變(bian)化的信道(dao)增益和(he)干(gan)擾等原因，使這個問題顯得尤為突(tu)出。

Besides the design challenges in the link layer,multiple transmitter and receiver pairs need to share the channel and an efficient channel access mechanism needs to be designed.
除(chu)了數據(ju)鏈路層設(she)計(ji)具有難(nan)度(du)之外，由(you)于多個(ge)發射機-接收機都需要(yao)(yao)共(gong)享該信(xin)道，因此還需要(yao)(yao)設(she)計(ji)一個(ge)有效的信(xin)道接入機制。

As we shall see, random access without centralized control can waste a great deal of the scarce resources in the network.
我(wo)們(men)應該看(kan)到，只(zhi)有隨機(ji)接入而無(wu)集中控制，會浪費網絡中大量的稀缺資源。