A large-signal dynamic model capable of modeling the transient behavior of the output power and wavelength of multielectrode DFB lasers is described. The key feature of the model is the use of a modified form of the transfer matrix method. Other features are the inclusion of spontaneous emission, longitudinal spatial hole burning, and nonlinear gain in the model. Results from the model demonstrate the important role played by longitudinal spatial hole burning in the chirping of DFB lasers and the limited use of tunability in controlling chirp.

The emergence of real-time services such as voice over IP (VoIP) and video streaming, imposes stringent requirements on the performance of a network if quality of service (QoS) targets are to be achieved. In the case of wireless networks, some form of radio resource management (RRM) is typically required to allocate the available resources among the contending stations in accordance with their needs and respective priorities. A critical aspect of any RRM scheme is the ability to monitor resource usage and to determine the resource requirements on a per-station basis. In this paper we describe a wireless traffic probe for IEEE 802.11 WLANs capable of obtaining this information and presenting it in a compact and intuitive format. The probe also shows how the wireless stations interact with one another in competing for the resources of the WLAN in a clear and quantifiable way. The results from the WLAN traffic probe obtained in a series of video streaming test scenarios are also presented that clearly demonstrate its usefulness and importance as a network tool in RRM and QoS provisioning schemes.

A numerical model for characterizing the steady-state operation of multielectrode distributed feedback lasers (DFB) is presented. The model is based upon the transfer matrix method which allows a wide range of structures to be analyzed. Using the model to compare a two-electrode device and a three-electrode device reveals that the latter has superior operating characteristics for tunability or FSK.

A Fabry-Perot interferometer based time-resolved spectral measurement system capable of transform limited performance is described here. The system results from a model developed for the Fabry-Perot interferometer from which the mirror reflectivity emerges as the critical parameter in determining both the temporal and spectral response. Using this system, the response of a multi-electrode DFB laser under a number of different modulation formats is investigated.

Power control techniques for IEEE 802.11 wireless networks have already gained much attention. Such techniques are particularly attractive because they can improve various aspects of wireless network operation such as interference mitigation, spatial reuse in dense wireless deployments, topology control, and link quality enhancement. However, until recently implementing such advanced power control using off-the-shelf wireless devices was not considered possible. For example, Abdesslem et al. [1] stated that ldquomany novel power control solutions cannot be efficiently implemented over existing IEEE 802.11 cardsrdquo. However, in this paper we demonstrate that power control is now feasible and can be implemented in current IEEE 802.11 cards with per-packet granularity and low power switching latency.