[資(zi)料來源: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
建立網絡化的(de)(de)無(wu)線(xian)控制(zhi)系統是一(yi)個極(ji)富挑戰性的(de)(de)任務(wu)。頻譜資源的(de)(de)稀缺對無(wu)線(xian)信道(dao)的(de)(de)工作(zuo)性能帶(dai)來了很大的(de)(de)限制(zhi)。隨機延滯(zhi)和(he)數據包丟失是不可避免(mian)的(de)(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(he)通(tong)訊網(wang)絡(luo)中都會出(chu)現類似問(wen)題，但在無(wu)線網(wang)絡(luo)中，由于(yu)頻譜資源和功率的(de)限制，以及隨時間變化(hua)的(de)信道(dao)增(zeng)益(yi)和干擾等原因，使(shi)這(zhe)個問(wen)題顯(xian)得尤(you)為(wei)突出(chu)。

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(le)數據(ju)鏈路層設計具(ju)有難度之外，由于多(duo)個(ge)發射(she)機-接(jie)收機都需要(yao)共享該信道(dao)，因此還需要(yao)設計一個(ge)有效(xiao)的(de)信道(dao)接(jie)入機制。

As we shall see, random access without centralized control can waste a great deal of the scarce resources in the network.
我們應該看到(dao)，只有隨機接入而(er)無集(ji)中(zhong)控制，會浪(lang)費網絡(luo)中(zhong)大量的稀缺資源。