We consider a covert communication scenario where a legitimate transmitter wishes to communicate simultaneously to two legitimate receivers while ensuring that the communication is not detected by an adversary, also called the warden. The legitimate receivers and the adversary observe the transmission from the legitimate transmitter via a three-user discrete or Gaussian memoryless broadcast cha...

In this thesis we investigate the capacity of multi-user wireless communication channels. We first establish a duality relationship between the Gaussian broadcast and multiple-access channels. This relationship allows us to characterize the capacity region of the Gaussian broadcast channel in terms of the dual Gaussian multiple-access channel, and vice versa. This relationship holds for constan...

is coming of age. In addition to reprocessed audio or video that's transferred from radio or TV to the Internet, webcasting now also means broadcasting new, original content—sometimes live— on the Web. Taking advantage of streaming audio and video technology, site producers can bring real-time sound and vision to the Web. With the present technology, audio and video must be compressed almost to...

The emergence of the Internet has forced a wealth of firms to explore a new form of channels of distribution, i.e., Internet channels. Nevertheless, empirical studies evaluating the values to firms from the adoption of Internet channels are limited. In order to fill in the literature gap, an empirical study to assess the effect of Internet channels on the market value was conducted in Taiwan. B...

First we consider compound channels which have common messages to all the receivers. The best-well known example is TV broadcast. Notice that compound channels are different from broadcast channels with independent messages to different receivers. Fig. 18.1 illustrates the encoding and decoding operations for the compound channel. Since the message is common, we have only one message w. From w,...

The rapid development of wireless communication technology and battery-powered portable devices is making mobile information services increasingly popular. Since the bandwidth resource of wireless networks is scarce and the mobile devices have a limited battery capacity, any solution for information access must be devised in such a way that time and power consumption for the devices are minimiz...

Wireless mesh networks (WMNs) which mediates the broadband Internet access, have been recently received many attentions by the researchers. In order to increase capacity in these networks, nodes are equipped with multiple radios tuned on multiple channels emerging multi radio multi-channel WMNs (MRMC WMNs). Therefore, a vital challenge that poses in MRMC WMNs is how to properly assign channels ...

With the increasing acceptance of wireless technology, mechanisms to efficiently transmit information to wireless clients are of interest. The environment under consideration is asymmetric in that the information server has much more bandwidth available, as compared to the clients. It has been proposed that in such systems the server should broadcast the information periodically. A broadcast sc...