Authored by:
 Collin H. Bruce
Satellite Radio Superstore
2007 (copyrighted & all rights reserved)

This guide is written to educate the end-user about the abilities and limitations of current generation XM & Sirius portable Satellite Radio Receivers; the Pioneer Inno, Samsung Helix& Sirius Stiletto.

Satellite Radio is a new and still-yet-growing technology. There are, however, some natural limitations to the technology as a whole that usually get washed-over by sellers and reviewers alike. The nature of the portion of the frequency spectrum (S-Band; 2.310 to 2.360 GHz) that is occupied by Sirius and XM Satellite Radio has some natural limitations that must be understood before one begins to build expectations of performance of a particular satellite radio product. These limitation and usage guidelines will be discussed here.

To be sure, satellite radio from both providers (XM & Sirius) has many advantages over terrestrial radio. It can, for instance, cover an entire continent with the SAME SIGNAL using but a few well-placed satellites. The satellite signal envelope could easily cover more than just North-America and the surrounding waters if more satellites were put in place. However, the main limitation of satellite radio lies with the intrinsic properties of the S-Band (2.310 to 2.360 GHz).

Rule # 1: S-Band does not transmit effectively through obstructions. Be it an awning, a thick oak tree, or the roof of a building, S-Band sees those as roadblocks. Most people expect the new portable satellite radio receivers (XM's Inno & Helix and Sirius' Stiletto) to receive a pristine and uninterrupted satellite signal even while in their basement or office building. It's an unreasonable expectation that stems from a lack of knowledge of the technology. And don't blame XM or Sirius for the limitation either, it was simply the only part of the frequency spectrum made available by the FCC for the broadcast of satellite radio. Only two licenses were granted for this narrow part of the band; XM and Sirius were the only licensees. In case you're wondering, no further licenses are planned to be put up for auction by the FCC for the immediate future (the next 5 years). Simply stated, don't expect portable reception inside of a building; there must be a line-of-sight and unobstructed view of the satellite to guarantee quality reception of a consistent nature. The same rule applies when aiming/situating one's home antenna.

Rule # 2: S-Band is CROWDED. There are substantial amounts of information being transmitted on adjoining frequencies both above and below satellite radio. Below, rests the Mobile Satellite Services portion of the band. This is a recently created band for small consumer devices utilizing satellite information streams. Above satellite radio we have the now ubiquitous 2.4 GHz wireless networking band. Both 802.11b and 802.11g utilize these bands and I'm sure one could imagine the amount of current (and anticipated future) traffic that these frequencies see now-a-days. The amount of information that is transmitted, whether in an area (a home) a region (satellite radio), or a hemisphere (MSS devices) is massive. One must consider that there might just be a little bit of interference between the millions of bits and bytes of data being transmitted on adjoining bands and the data being sent for satellite radio. The crux of the matter is, if there is occasional interference with one's satellite radio, one must consider that the source (which is 40 thousand miles overhead) has some competition when trying to deliver the signal to the end-user.

Rule # 3: Battery power can be limited on portable satellite radio devices. I don't think it is hard to imagine how a device that is barely bigger than a 5th generation iPod video could experience shorter-than-average battery life when attempting to receive the faint signal of a satellite that is 40 thousand miles overhead, and often traveling and many times the speed of sound (this is true for Sirius, XM's satellites are geostationary). Satellite radio reception technology was derived from hand-held GPS receiver technology. On top of simply displaying information, the satellite radio device must also decode the compressed bit-streams into data that is usable by the device, use another set of processors to control which specific channel is tuned-in, use still another set of processors to control the audio portions of the experience (i.e. audio equalization, tone settings, favorite stations, volume, the control surfaces and buttons, and the often multi-color display w/ fancy graphics). In addition to this, the Inno/Helix and Stiletto must cram a respectable amount of non-volatile flash memory (usually 1 to 2GB) to store recorded and imported music on the device. These two devices must also run an operating system (however simple) underneath all of this. In essence, to have a satellite radio that is barely bigger than an iPod Video is amazing. Battery life is nominal and respectable when considering the litany of tasks that must be performed on a small-scale inside of the units themselves. Between 4 and 8 hours of usage would be unimaginable even three years ago.

In sum, it is vital to adjust our expectations of performance of any given item based on reality and not fiction or some unfounded preconceived notions. It is easy to bash the 'lack of performance' of the new generation of portable satellite receivers. One must fight this urge and take an objective and practical approach toward satellite radio's performance. Does one expect a car to jump 40 feet in the air (like in Dukes of Hazard) and land unscathed? We can barely drive quickly over a speed bump at a brisk pace without wondering if our cars or trucks will hold together. Satellite radio is a new technology that begs for innovation and advancement. Improvements will continue to be made and new products unveiled. As I recall, it wasn't all that long ago that 10-15ft diameter receiver dishes were required to receive satellite television. Until the future arrives, the technology and performance that we currently have in XM & Sirius really isn't that bad at all. In fact, it's pretty amazing.