Following a period of spectacular growth, basic wireless services have reached a high penetration, although most of the 3 Billion or so subscribers across the Globe still rely on voice and low-rate data communications. Naturally, the provision of sophisticated multimedia "tele-presence" services requires a further quantum leap from the current state-of-the-art represented by the popular mobile telephone...
This research-oriented panel will embark on speculating on the future directions of the broad field of wireless multimedia communications, with a view to involve you, as a fellow researcher in outlining a range of open problems for our research community to address.
Commencing with a brief historical perspective, the panelists outline a range of challenges related to wireless multimedia communications. It may be argued that 'point, shoot & share-style' video communications may result in the 'world-wide-wait' owing to the potentially excessive offered teletraffic, since the wireless channel has to obey the Shannonian information-theoretic lessons.
A substantial capacity extension is offered by the employment of sophisticated source and channel coding as well as multi-functional smart antennas, which will be elaborated on with specific reference to next-generation wireless enabling techniques. Unfortunately smart antennas fail to reach their full potential under realistic shadow-faded propagation conditions, unless their cooperation-aided counterparts are employed. Alternatively, they have to be combined with HSDPA-style adaptive modulation and coding.

The cross-layer optimized next-generation adaptive modulation and coding assisted transceivers are expected to simply 'instantaneously drop the throughput, rather than dropping the call' by reconfiguring themselves in a more robust mode of operation with the aid of adaptive slot classification. Novel multiple access techniques, such as Spatial Division Multiple Access (SDMA) and Interleave Division Multiple Access (IDMA) also offer substantial throughput improvements, especially with the aid of transmit preprocessing at the Base Station (BS), provided that sufficiently accurate channel estimates can be provided by the mobile stations for the BS’s future down-link transmissions.
The basic rationale of the MIMOs' success is that they are capable of breaking free from the channel capacity limitations of classic Single-Input Single-Output (SISO) systems obeying the Shannon-Hartley law, provided that their antenna elements may be positioned sufficiently far apart for ensuring their independent fading. This is however rarely the case in realistic shadowing environments, where again, adaptive modulation & coding as well as cooperation may be able to prevent the erosion of the MIMO capacity.
This panel aims to involve our research community in outlining a range of open problems and defining a roadmap for solving them. In the current era there is still a substantial gap between the theoretical predictions and the practically attainable performance of wireless systems. A particularly challenging research driver is constituted by the Wireless Internet, especially when considering immersive high-motion, high-resolution applications. Thousands of researchers address the problems of ad hoc networks, but the theoretical predictions of Gupta and Kumar indicate that their per-node capacity tends to zero upon increasing the number of nodes supported by the network. What are its ramifications for the worthy cause of the global 'one-laptop-per-child' project?
Clearly, further quantum leaps are required, in order to avert the threat of the 'world-wide-wait' in the emerging wireless Internet. Do join us for an enlightening discussion!