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The exploration is built upon Delphi's, Nissan's, Cohda Wireless' and Savari's experiences in Asia, Europe and U.S.A. It describes and derives lessons from all four companies' contributions in projects such as SMARTWAY in Japan, Drive C2X and in Europe, as well as the Connected Vehicle Safety Pilot in the U.S.A. All the above programs were implemented by means of the Dedicated Short Range Communication (DSRC) technology in the SHF spectrum based on the IEEE 802.11p/Wireless Access in Vehicular Environments (WAVE) standard. The study is supplemented with insights regarding complementary technologies such DSRC in the lower UHF frequency band (i.e. 700 MHz) as well as a V2X implementation through the 4G LTE (Long Term Evolution) cellular telecommunication technology. This paper addresses issues regarding the physical layer (PHY) of the DSRC system. The combination of the delay profile caused by multipath propagation along with the motion-based Doppler spread leads to time and frequency dispersion. This limits the number of bytes acceptable for reliable communication or requires a solution at the receiver end. The analysis of the Doppler spread shows that DSRC implemented at 700 MHz is more immune from data packet length issues as opposed to 5 GHz DSRC. On the other hand, 700 MHz DSRC exhibits a much longer delay spread. Thus, guard time interval specified in ASTM E2213-03 cannot be applied as is to 700 MHz DSRC. This paper refers to the German project CoCarX and the Japanese SKY for pedestrian for studying the feasibility a V2X system built on the 4G/LTE technology and its infrastructure. It provides on a vision for an accelerated V2X deployment based on a heterogeneous system. Last, we recommend the ITS stakeholders to carry out extensive research and validation works on DSRC capacity for ensuring a large scale deployment.

This paper summarizes recent progress that has occurred in several research areas related to the development of a repetitively-pulsed, frequencyshifted chemical oxygen iodine laser (COIL). COIL gain-switch experiments at 10 kHz pulse rates are described using a novel solid state pulsed magnetic field system. Raman conversion experiments in hydrogen using a pulsed photolytic iodine laser as a COIL surrogate are also described. INTRODUCTIONThis paper summarizes the current status and results of the COIL Illuminator Program being conducted at the Air Force Research Laboratory to provide alternative beacon illuminators for Air Force application. This program has been on going for several years and has been conducted primarily as an AFRL in-house program with support from several SBIR contracts. The AFRL provides program direction and experimental facilities for the gain-switch testing, STI-Optronics is responsible for developing the gas RAMAN system, Aculight is developing the seed laser, NSRC developed the magnetic field pulser system and Logicon provides the gain-switch perfonnance predictions.The COIL illuminator concept is shown in Figure 1 and consists of the COIL laser system, a pulsed magnetic field system on the cavity, an injection seeder and Raman conversion system to produce a pulsed, mode-locked and frequency-shifted output laser beam at 1.42 microns. This system is scaleable from 10 kW average power to several hundred kW in a weight efficient manner. The remainder of this paper will describe the results of research efforts conducted over the last year to demonstrate several key technologies that make the COIL illuminator concept a viable system. These efforts include the RADICL gainswitch II experiments conducted at AFRL and the hydrogen Raman conversion activities at Aculight and STI Optronics. GAIN-SWITCH IIThe goal ofthe Gain-Switch II experimental effort was to demonstrate gain-switching ofa COIL device (RADICL) at 10KHz repetition rate, with short pulse widths, <4j.ts, and see a significant enhancement in the peak power to CW power ratio (as compared to OS-I). This was achieved by incorporating the Solid State Pulser system designed and built by Northstar (see section 2.1) with the RADICL device and designing the flow conditions, resonator and diagnostics needed to test the performance ofthis system. The OS-Il testing on RADICL was successful in meeting the 10kHz and short pulse operation but the peak-power to CW-power ratio was not as large as expected. The OS-I! test results did not yield an enhancement of the peak to CW power ratio over the OS-I test results'(jeak to CW power ratio of 12.7). There will be more discussion in the results section 2.3.