[資料來(lái)源:網(wǎng)絡(luò)]

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
建立網(wǎng)絡(luò)化的無(wú)線控制系統(tǒng)是一個(gè)極富挑戰(zhàn)性的任務(wù)。頻譜資源的稀缺對(duì)無(wú)線信道的工作性能帶來(lái)了很大的限制。隨機(jī)延滯和數(shù)據(jù)包丟失是不可避免的。

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(wǎng)絡(luò)中都會(huì)出現(xiàn)類(lèi)似問(wèn)題，但在無(wú)線網(wǎng)絡(luò)中，由于頻譜資源和功率的限制，以及隨時(shí)間變化的信道增益和干擾等原因，使這個(gè)問(wèn)題顯得尤為突出。

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.
除了數(shù)據(jù)鏈路層設(shè)計(jì)具有難度之外，由于多個(gè)發(fā)射機(jī)-接收機(jī)都需要共享該信道，因此還需要設(shè)計(jì)一個(gè)有效的信道接入機(jī)制。

As we shall see, random access without centralized control can waste a great deal of the scarce resources in the network.
我們應(yīng)該看到，只有隨機(jī)接入而無(wú)集中控制，會(huì)浪費(fèi)網(wǎng)絡(luò)中大量的稀缺資源。