dmchssc

How significant is the range boosting effect of MIMO? Is the LTE airlink so fragile that it's still needs a 10 dBm stronger signal than CDMA technologies even with the effect of MIMO?

There is a difference, but for all intents and purposes, the end user will not notice a difference on the downlink. Most of the benefits are related to interference management. Carriers will more easily be able to deploy microcells and femtocells in congested areas with the implementation of LTE advanced.

I would think that 4x4 MIMO support in handsets would be very limited. For tablets, etc, sure. But supporting multiple bands and having four antennas just doesn't sound feasible except with especially large devices. BRS would be the only one I'd expect to see anytime soon. Anyway, 4x2 (at least, maybe 4x4) MIMO is supported in Rel 8. LTE-Advanced isn't a prerequisite.

Edit: Does anyone know if Sprint's LTE hardware supports more than 2x2 MIMO as currently deployed?

Ideally, all the carriers should do this. No more cross-subsidization of expensive devices and upgrades from people who don't upgrade or buy cheaper devices. Most European carriers sell plans this way.

LTE Advanced doesn't really increase spectrum efficiency. It's mostly network-optimization features and carrier aggregation.

Based on a few new points in Sensorly, it looks like there's finally an active site in Back Bay. That was one of the last major areas I regularly go to in Boston that didn't have a usable LTE signal. I'll probably try to map the area soon.

The highest of the two will likely determine whether you get a usable LTE signal or not. Your 1x signal is probably weaker because the carriers colocated with the EVDO carrier you're on probably have a worse EC/LO ratio than the one your phone chose.

It was a priority in Chicago because of two factors that aren't affecting any other big markets. Chicago is spectrum-constrained for Sprint, and because of incompatibility between NV and legacy base station equipment, call-dropping became a huge problem shortly after roll out began. Deploying 800 MHz helps both of these problems. The spectrum problem is improved because it adds another 1x carrier on a previously unavailable slice of spectrum. Dropped calls are reduced because 800 MHz has more coverage than 1900 MHz, so handsets can hold a call for a longer duration without needing to switch towers.

I have a pbxes.org account set up with my Sprint-integrated Google voice account. Using CSipSimple or the built in SIP client on some ROMs, I can do WiFi calls using my Sprint number. I've found that using SIP provides a much better experience than using something like GrooveIP. Latency is better, and the connection is much more robust. It can even do hard-handoffs between WiFi APs and cellular data. Audio is lost for the time without data, but the call doesn't immediately drop. In my experience, the interruption is typically less than half a second.

Do people seriously want some gaudy logo in their status bar to let them know they're on LTE? "4G" is simple and fully informative.

Are you referencing this post?

 

 

 

If so, keep in mind that circuit switched voice and VoIP are two different animals. Traditional circuit switched voice via CDMA1X can take advantage of variable rate codecs and does not require routing info be included in the data stream. For a counterexample, Google Talk, which can be leveraged by Gmail and GrooVe IP integration for VoIP calling, uses the G.711 codec at 128 kbps (64 kbps each way) plus routing info for a total bit rate of approximately 160 kbps.

 

VoIP is much harder to do well, especially with mobile. This is why I am in no hurry to replace gold standard CDMA1X voice with questionable VoLTE.

 

AJ

What about the newer, more advanced codecs like Opus? They can provide HD-Audio quality (for voice) with 10 kbps.

Dish doesn't have enough spectrum to be able to compete effectively on its own. A merger between either Sprint or T-Mobile with Dish would probably be approved, but not one between Sprint and T-Mobile themselves.

The FCC has plenty of people who are way more knowledgeable and intelligent than I am. That idea is simple enough that I'm sure it's been thought of before. The major barrier to it would be the need for the government to vacate the 1700 MHz spectrum. I think that would require an act by Congress. I'm just questioning Dish's essential assertion that Sprint is just trying to steal their spectrum. They don't have a deployed network or deployed devices, and Sprint is proposing a band reorganization that would significantly increase the amount of usable spectrum.

When did the standardization process for the band as currently defined start? Would it take more than a year to get through the process again if the band was redefined?

T-Mobile might have their 2G network configured to use full-rate because most of the load has moved to 3G. Sprint, especially in spectrum-constrained Chicago, may have to use higher compression modes in some areas.

I thought Sprint was requesting that the AWS-4 uplink be shifted up by 5 mhz, not to place power restrictions on it.

Edit: I just looked at the FCC's spectrum dashboard. If the government vacates 1755 - 1780, the AWS band could be expanded to 1710-1780/2110-2180. That gets rid of the AWS-2 downlink (non PCS H block) at 2175-2180. Then, proposed AWS-4 could have its uplink shifted up by 5 MHz, taking out the uplink of (non PCS H) AWS-2.That would leave a 5 MHz guard band that could be used for low power applications in-between PCS H and the AWS-4. The new bands would be PCS (1850-1920/1930-2000), AWS-1 (1710-1780/2110-2180), and AWS-4 (2005-2025/2180-2200).

That plan would find a use for the oddball AWS-2 spectrum and expand usable spectrum by 100 MHz compared to an expansion of only 40 MHz if the AWS-4 (2000-2020/2180-2200) configuration is used.

This means that Chicago goes from a relatively spectrum poor market for Sprint to a relatively rich one.

There is a mechanism by which cell edge users are handed off to roaming if voice carriers are under heavy load. It's not so much something done by the network as something fundamental to CDMA. The heavier the load on a voice carrier, the more effective cell size shrinks. It simply gets too noisy for handsets with weak signals to hold a working connection. This causes them to go to roaming.

My 3G speeds have been decent recently, but I find myself using less than a gig a month. I'm at a university, and everywhere indoors on campus has a 20+ mbps WiFi connection. So, I use WiFi probably 90% of the time. According to my data stats, I've used 3.66 GB of data on WiFi since the 9th, but only 120 MB of mobile data.

I'm using Sensorly on my Galaxy S III with CyanogenMod 10, and I've mapped a lot of LTE coverage in the South End of Boston. 3G doesn't seem to record signal strength correctly though. Even when I have one bar in an area, it still reports full signal on the map.

Metro already has roaming agreements with Sprint and Verizon. Sprint appears as native coverage, and Verizon coverage is free-texing and $0.25 (or something higher) per-minute voice. I'd expect those agreements to carry over in a merger, at least for existing subscribers.

Isn't channel 28 just a regular channel in the PCS A block?

I've been wondering about AWS vs PCS tower spacing. The downlink on AWS has worse propagation characteristics than on PCS, but the uplink is better. Since the uplink is typically the first to fail, it is more important when considering tower spacing. In most/many situations, I would think transmit power on AWS could be increased to compensate for weaker downlink propagation vs PCS. This would mean that the tower spacing could be the same or even a bit wider for AWS.

Is this accurate?

I haven't seen anyone post saying they have CM10 and connect to LTE. Could be the ROM.

I've been doing it. The 4G/3G handoff is non-existent though. When I lose 4G, I lose data completely for several minutes or I manually toggle airplane mode. I mostly keep my phone on EvDo/CDMA only mode because I only get LTE in a neighborhood I only visit occasionally.

No, Boston.

I got 4G in the South End yesterday. Signal was weak on the Huntington side of the corridor park, but speeds were good everywhere from the corridor at least to Tremont for at least several blocks north of Mass Ave.