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Software-Defined Radio Could Unify Wireless World
mjdroner writes "Technicians in Ireland are testing a device capable of skipping between incompatible wireless standards by tweaking its underlying code. The article states: 'The device can impersonate a multitude of different wireless devices since it uses reconfigurable software to carry out the tasks normally performed by static hardware. The technology promises to let future gadgets jump between frequencies and standards that currently conflict. A cellphone could, for example, automatically detect and jump to a much faster Wi-Fi network when in a local hotspot.'"
I'm not much of a hardware person, so maybe I'm missing something, but aren't different types of antennas needed for different applications? Isn't the best size of antenna a function of its frequency? I understand how you can use software to replace some of the active circuitry, but how are you going to change the size and shape of an antenna via software?
Why spend that much ($350+), when you can order a dirt-cheap shortwave radio for maybe $40 and just use a simple 455 kHz to 12 kHz adaptor?
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
It would be nice except Slashdot has been posting something about software radio for years and still nothing. Other factors to consider:
1) Power consumption on software radios will be much less efficient than their analog counterparts
2) band limited to certain frequencies - relevant because higher powered transistors at higher frequencies are becoming available, pushing beyond the 2.5 GHz limit we have right now (compliments of Gallium Nitride and Gallium Arsenide).
Cognitive radio is a concept very related to this discussion. I googled a little about SDR and cognitive radio and came across some interesting paragraphs. Short Definition of SDR: Software defined radios are making it possible to change waveform properties and applications while operating in the field via the addition or upgrade of software. For SDRs, reprogramming or upgrading a single radio or a radio network takes about as much effort as upgrading a computer's operating system or program options. US Army interest : For its part, the U.S. Navy is likely to be the largest consumer of software defined radios with the military's Joint Tactical Radio System Initiative (JTRS) radios following closely behind. For the Navy, the software-based Digital Modular Radio (DMR) is replacing a roomful of radios with a single rack of DMRs. The DMR is a four-channel, full-duplex system that is essentially four radios in one. Currently operating on submarines and surface ships around the world, the DMR (AN/USC-61) is successfully demonstrating the viability of software defined radios on active duty. Cognitive radio: The cognitive radio, as its name implies, builds on Software-defined radio to carry a level of cognition or intelligence that permits decision-making and learned patterns of behavior. According to IEEE, the cognitive radio is a radio transmitter/receiver that is designed to intelligently detect whether a particular segment of the radio spectrum is currently in use and to jump into (or out of) the temporarily-unused spectrum very rapidly without interfering with the transmissions of other users.
This isn't all that new. It's just becoming cheap enough that it's worth doing for single-channel units.
For some really interesting reading on software defined radios, do some research on the DoD's program called Joint Tacticle Radio System (JTRS). The goal is to replace ALL radio's in the DOD and other government agencies (think police, fire, ems, homeland defense, fema, etc as well as coalition countries) with a JTRS radio (in a few different form factors) using standard waveforms that are kept in a single library to ensure compatibility. The basic chasises will use pluggable modules for both "standard" waveforms as well as others that require either highpower, atypical freqs, as well as modules for encryption. the base system will be able to act as a gateway for compatible msg types on different wave forms allowing joining of systems that previously are not able to share traffic.
... as well as some other very nifty features.
... and those are IMPOSSIBLE to get without a "if we don't have this now troops will die YESTERDAY" justification.
Then of course there is the Wideband Networking Waveform (WNW) which will also go on the JTRS radio. THAT is an interesting beast that is VERY ambitious. Not sure how much info is out there open source (even the unclass stuff) but whatever is out there should prove intersting. WNW is planned to be the SINGLE waveform for all DOD use after they phase out the others sans uber special ones like ULF for subs, etc. Think a completly networked battlefield for text, voice, video, and data on land sea and air, that can dynamicaly heal and reroute itself as nodes come on and off the network (for whatever reason be it "death" or loss of connectivity) all while keeping special forces hidden (but still connected), ground pounders situationally aware of where other friendlies are and where we know the enemy is via a networked display, instant access to survielence at the lowest levels and doing it all while under electronic attack
To put it in perspective of how serious they are: NO ONE in the DOD is allowed to buy ANYTHING that isn't JTRS compliant without a waiver from the SecDef level
In software radio utopia the bitch down the street would have a software radio that would automatically range the boyfriend and select a band that allowed for the most efficient and localized transmission. Which I sincerely doubt would be your precious highly regulated HF band.
In software radio utopia the radios would only invade low bit per second "buggy whip" HF bands when something like a category 5 Hurricane Zelda struck and knocked out the local high bandwidth high frequency ISP nodes.
And even then a UHF or VHF band would be more likely to reach a functioning ISP node. So don't get your HF panties in a bunch.
Here in Seattle I've often found my Verizon EVDO is faster than T-Mobile's Starbucks or Border's WiFi hot spots.
And what if I'm on the bus traveling down the street: 3G, WiFi, 2.5G, WiFi...
The decision to switch from 3G to WiFi will have to be made on more complex criteria than simply "Oh look WiFi!!"
Right now my Tablet PC can't even handle going "Hey Wifi!" reliably, although Mac's do it quite well.
And I can't even begin to picture how one would handle a TCP hand off with out using IPv6. RIght now Verizon and CIngular both suck at handing off seamlessly from 3G to 2.5G and back to 3G when running around in a bus on their own networks (where they have control over IP addresses' and routing).
I submit that these issues push things further out than you think to achieve your utopia.