LTE in the unlicensed 5 GHz spectrum is coming soon (since the cell companies somehow only just realized that even if it's not pristine spectrum they also don't need to pay billions of dollars to access it) so there will actually be a legal way to use this in the future.

Just to make it clear - current "unlicensed" LTE technologies are LTE-U and LAA require an "anchor" channel in a licensed band. I.e. you still can't run it in your home unless you have a license for one other spectrum band. It's still limited to a carrier play, unfortunately. There is MuLTEfire tech by Qualcomm which can supposedly work completely in unlicensed spectrum, but it's proprietary and not very much is known about it so far.

Yeah no. This isn't LTE that anyone can set up, like WiFi. It's more designed to improve the speed of licenced LTE by letting LTE femtocells use unlicenced bands.

Also only the downlink is done over unlicenced bands. There's a competing standard that does uplink and downlink, but the all just augment a licenced LTE connection.

Any details on handset availability (even rumors)? I'd love to get my hands on a phone with an LTE transceiver that can operate in this spectrum range having an unlocked bootloader on the application processor.

Setting up a base station at elk camp and being able to use a regular cell phone instead of a dedicated amatuer or FRS/GMRS transceiver would be very cool.

Sorry, I don't know when this stuff is coming. In the mean time you could just use a wifi network with a SIP server for voice calls.

How is that going to work? I thought 5GHz had really poor penetration and attenuation. Will it trash wifi performance?

The cell carriers are mainly planning to use the 5GHz band for small cell indoor deployments (distributed antenna systems). The 3GPP and the Wi-Fi Alliance are going back and forth to ensure that if LTE and Wi-Fi networks are forced to share the same channel that it will at worst degrade the Wi-Fi performance as if there were another Wi-Fi network sharing the channel.

> ... if LTE and Wi-Fi networks are forced to share the same channel ... at worst degrade the Wi-Fi performance as if there were another Wi-Fi network sharing the channel.

All Our Shared Spectrum Are Belong to Us [32c3] https://www.youtube.com/watch?v=9cZxMg8shbA#t=1193

Unfortunately that's not true in implementation because LTE-U doesn't know or care about the wifi channel announce timings. By piping up whenever it wants to wifi throughput actually degrades more than 70% at minimum LTE-U duty cycle spec (50%) and up to almost completely, ~99% reduction, at max allowed LTE-U duty cycle (90%) spec.

No matter what they say this is a spectrum grab and LTE-U will degrade 5 GHz wifi to the point of being unusable.

Software defined radio such as hackrf can use this.

HackRF can't do it, because it's only half-duplex. But there are plenty of full duplex SDR devices - check out UmTRX and USRP B210. We're also developing a really tiny high performance SDR specifically for LTE - http://XTRX.io

Are you sure? hackrf usually can only provide half-duplex operation, and somewhat full duplex after certain tweaks. Still usb2.0 will be a limiting factor in this case. USRP boards will probably be a lot better.

HackRF/USB2 has enough bandwidth to do LTE, particularly since LTE can be configured to use between 1.4 and 20 MHz. I think the lack of full duplex or an FPGA on board would be the major limiting factors.

As mentioned above, half duplex of HackRF would be a limiting factor, unfortunately.

Obviously but you need to TX/RX on some sort of frequency otherwise it's not really a radio :).

I was just wondering if there's spectrum allocated for experimentation or if you'd be stepping on FCC rules by putting this into practice.

If you're running both sides on SDRs you should be able to tweak the frequencies in use. Several LTE bands neighbor and/or overlap amateur radio bands, so adjusting the settings a bit should allow you to move your test operations in to a range that is trivial to gain permission to use.

Bands 30 and 40 actually exist entirely within the amateur 33cm band, band 42 overlaps with 9cm, and band 46 overlaps with 5cm. Two of those also overlap with unlicensed spectrum, so there's extra room to play in that no one reasonable expects those bands to be clean anywhere people have electronics.

If you have cooperative endpoint devices you could also bodge other more common LTE bands in to amateur frequencies. Band 31 is just a 20 MHz drop away from fitting in 70cm, and cutting down the duplex spacing could make part of band 8 usable in region 2.

If you want commercial hardware to work it's probably best to stick to the first group, but if you're doing SDR on both sides and just want to experiment the second group should technically work.

Speaking of UEs (aka LTE modems) - there is an open-source implementation add well. See srsUE and srsLTE.

The BladeRF or the upcoming LimeSDR can handle this.