Currently viewing the tag: "MetroPCS"

Metro announces they sold their first VoLTE phone in the Dallas market tonight (07Aug12), the LG Connect 4G Android™. This is a necessary step for Metro as they will now be able to offer simultaneous voice and data for the first time now (SVLTE) and helps address the lack of spectrum they face in a few markets. I imagine they will w

ant/need to go down from AMR 14.4 voice coding in the future (default for VoLTE) due to the lack of efficiency compared to the EVRC-B that they are using today but they can surely start there. Also note, with the IMS client on the LG Connect, this device can also technically (InterRAT) handover to a WiFi channel (assuming they have deployed edge security and ePDG in the network), so they can technically have offload very rapidly, no small cells to deploy. This could be very interesting.

BTW, SK Telecom and LG Uplus announced their launches today too, so there was apparently a race on to be the first in the world, although the Korean launches seem to feature HD voice with a wideband Vocoder.

Gold/silver/bronze finish for US and S.Korea…


The full Press Release is at the bottom…

 Now full disclosure here: I have been involved with MetroPCS’s (again should we go to MetroLTE?) LTE involvement from the time it was a what if scenario. OK, fast forward…so I’m reading Bloomberg, Reuters etc… and they are going on about the good results from MetroPCS. Let’s review. Reuters specifically says: 

At the end of the second quarter, the company said, about 8 percent of its subscribers were using its so-called fourth generation high-speed service, which is based on a technology known as Long Term Evolution.

The company’s service revenue rose 4 percent to $1.16 billion for the quarter. Quarterly average revenue per user was $40.62, up 13 cents from a year earlier.

MetroPCS posted a net subscriber loss of 186,000 in the second quarter. Analysts had been expecting its subscriber numbers to fall by 94,000 to 174,000, according to four analysts contacted by Reuters.

The company said it expects to boost subscriber growth with 4G LTE For All, a line of affordable 4G LTE smartphones it plans to launch in the second half of 2012.

“During the fourth quarter, we expect our 4G LTE For All initiative to lead to a return to subscriber growth,” Chief Executive Roger Linquist said in a statement.

Churn — or customer defection rate — fell by half a percentage point to 3.4 percent for the quarter.

So the key points that stuck out to me are:

  • Metro is shedding their prepaid voice subscribers but gaining sticky LTE subscribers. 
  • Metro expects to grow subscribers- LTE subscribers
  • OPEX doesn’t seem to be out of control with prepaid all you can eat LTE data users.
  • They are planning to refarm their CDMA spectrum using VoLTE and presumably an all LTE device line up.
  • Churn is down so customers seem to be happy
MetroPCS deployed LTE on their existing AWS and PCS spectrum. Many said they couldn’t be successful on such limited spectrum. Metro even made tough choices with their towers and antennae to deploy but not break the bank. That took some courage. Also worth noting, they are completely prepaid so customers are buying these smartphones outright. LTE smartphones to boot.
So the big (public) bets placed by Metro’s exec team like skipping EVDO and heading for LTE with their prepaid customer model intact seems to be working for them. This is a good thing for MPCS shareholders but a really good thing for consumers (with an interest in wireless services) in general. It must have been a moment to sit in their conference room and get the news that the bets are paying off. So obviously they have their work cut out for them, they need more LTE devices from more OEMs, they need more spectrum to both improve performance and meet the demand from their growing customer base, and to do that they will either need to buy more spectrum or deploy VoLTE (with the associated IMS integration, UE clients etc…) to help them refarm the existing CDMA spectrum. That’s a lot to get done!
Go MetroPCS!

MetroPCS Launches World’s First Commercially Available Voice Over LTE Service and VoLTE-Capable 4G LTE Smartphone (via PR Newswire)

DALLAS, Aug. 7, 2012 /PRNewswire/ — MetroPCS Communications, Inc. (NYSE: PCS) today reached another innovation milestone by announcing the world’s first commercial launch of Voice over LTE (VoLTE) services, availability of the world’s first VoLTE-capable handsets and the first sale of a VoLTE-capable…

Read Full Article →

 RootMetrics has been publishing network performance results. The latest one shows the discrepancies in LTE/WiMax/EVDO in the Las Vegas Market. It’s an interesting read but take this all with a large grain of salt as I have noticed that there are lots of reasons for the performance skews for ATT, MetroPCS, Sprint and VZW. Not saying their data is invalid but I do know of lots of issues behind their numbers that I’m probably not at liberty to discuss so draw your own conclusions… Full Las Vegas Report is here…

 All of their reports are here.

From the Las Vega$ report:

We’re back for more!

This report marks our second visit to the Las Vegas market, having also tested the area in November of 2011. We found some notable changes that might impact your mobile service decisions.

  • By far, the most significant change was AT&T’s LTE network upgrade and the dramatic impact it had on their data speeds: AT&T’s average download speed increased from 3.3 Mbps to 16.2 Mbps, while their average upload speed increased from 1.2 Mbps to 5.4 Mbps.
  • Though not nearly as dramatic as AT&T’s improvement, T-Mobile and Verizon each recorded faster average download speeds this visit compared to what we found in November.
  •  The speeds recorded by Cricket and Sprint showed small variation from what we found during our previous visit. MetroPCS was slower this time than what we found during our previous visit.

    Data performance

    RootScore Award winner: AT&T and Verizon


 There is an interesting flow of comments coming out of the Barclays Capital High Yield Bond and Syndicated Loan Conference. Firstly there was some interesting comments by MetroPCS regarding LTE, these are from Keith Terreri VP, Finance & Treasurer, MetroPCS Wireless, Inc.

  • Firstly they have accumulated 500K subscribers so far out of between 9M-10M total subscribers. 
  • They are looking for more spectrum and are high on LTE, with over $1B allocated to spectrum allocation.
  • Metro is working with Asian suppliers to introduce ~$200 LTE/Android UEs. Remember, Metro has deployed primarily in 3GPP Band 4 (AWS) with a few markets in (PCS) Band 2. 
  • They are pretty constant in EBITDA although there’s a severe market environment that puts lots of pressure on their prepaid subscribers, and competitive pressure on they voice minutes. Thus it’s probably fair to say LTE is helping the margins. 
Joseph Eutenuer, CFO of Sprint Nextel Corporation presented their network vision. Some tidbits:
  • Steve Elfman’s group doing well getting construction permits for their 6 markets. (Means it’s verrry early in their deployment!) Sprint is deploying  LTE in 3GPP Band 25, turning off iDEN (push to talk), and consolidating site infrastructure…
  • Sprint sort of preparing for LTE iPhone. Have a similar contract with Apple to Verizon Wireless and ATT so they will be able to offer it as well.
  • They feel confident they will sell LTE iPhone even without extensive LTE coverage initially.
Slides regarding Sprint’s Network Vision plan…  OET and PSHSB

 Here are some thoughts about the questions I get around SVLTE.

Notice the pic and remember this day? This was Verizon and Apple answering questions about the iPhone 4. The biggest technical tidbit of the day was that the 3G iPhone 4 would not allow a simultaneous voice and data session. Of course this was dictated by the 1X CDMA network architecture, not the phone.

Here is a good graphic sort of illustrating that difference.  

Yes, The same issue exists for LTE and CDMA voice!

See, there is a confusion based matrix of items to enable the use of data during a voice call. There is some technical detail to get into to understand what the problem is.

Some of the blame goes to the phone OS, some the phone HW and some is on the network.

HSPA/WCDMA 3GPP networks like ATT and Tmobile support this feature and so the remainder is inside the mobile device. 3GPP2 based Verizon and Sprint on the other hand don’t have this capability inherently in the network. 


UE (Mobile Device) UI Capability/function

The device User Interface (UI) manages the integration of voice and data services for us. As you know, for example, the iPhone visually displays a dial pad for voice calls and has other apps for data like browsers, email, FaceTime/Skype etc… Not so obviously, the multitasking nature of the UI and Operating System  that supports multiple execution threads etc, facilitate and encourage data use such as it is so convenient. The interface makes it easy to switch between these tasks and actually encourage parallel data/voice simultaneous use. So Smartphone = Attention Deficit Disorder (ADD) device.

UE (Mobile Device) Hardware (HW)

Beyond the user interface, the device needs to be enabled with the capability to transmit data and voice simultaneously (or apparently so.)

Many USB based devices are data only (much like the old flip phones were primarily voice only) and only have HW to facilitate a data transmission. No voice HW present, but no need either. Result is simple and cheaper device. Smartphones sort of beg dual use, and often have HW to support data transmission and voice encoding/transmission. Now for the caveat (confusing part), of course it’s possible to have a data application for voice like Skype and that would technically eliminate the need for separate HW however the first deployments in the US are only partial data overlays over extensive voice networks, thus most devices base their connectivity on 3G voice and need to have voice compatible HW onboard for those non 4G or 3G data covered areas. Secondly, the quality of voice in voice networks is currently more assured, or higher priority than the existing non assured data services. So in the case of Skype over 4G, your voice packet gets the same priority (currently by default) as my web browsing packet. (With the PCRF this doesn’t have to be true but operators have not really unleashed this tiered type of service over LTE yet.)

So hardware wise, UEs utilize (baseband) processors capable of 3G to in addition to LTE to be capable of communicating with both networks. The first devices had 2 chipsets, 1 for 3G processing and a second for LTE processing. Only recently has there been multi generational (and multi protocol) capable chipsets that are able to process both 4G data and 3G in one chipset. 

To be clear, a device that has a single RF/baseband processing path may only be communicating on one network at a time.

Here is a typical data + voice capable device architecture showing Qualcomm components. 

So if the processing is in place, the next thing in the chain is the Radio Frequency (RF) chips. You can’t physically interface to the network without the capabilities here so it’s essential for the device to be able to interface to the voice and data spectrum bands and modulate/demodulate the signals correctly. This whole subject is so deep, more in a follow up post on this.

 Qualcomm is arguably the market leader in UE components and architecture. The pictures are the previous MSM8960 components which were 2 pieces of silicon for 3G and 4G processing and others for RF. The MSM9600 chipsets that are shipping now are essentially 1 piece of silicon for 3G and 4G processing with a second for the RF interface.

UE Network Communication Protocol

In the US, MetroPCS, Sprint, US Cellular, Verizon are networks that utilize CDMA 1X technology. 1XRTT (IS-95)/CDMA2000 or 3GPP2 based voice is a circuit switched voice protocol, with all the bells and whistles of 1.25MHz channels, RCs, Walsh codes, PNs etc… For high rate data, these networks utilize 1xEVDO (Evolution Data Only) a code and time division protocol and have slots, 1.25MHz channels, DRCs and so on. In summary, CDMA2000 uses 2 separate radio channels with 2 protocols for data and voice communications. ATT, T-Mobile and others have deployed 3GPP based WCDMA networks with 5MHz channels for voice and HSxPA with 5MHz channels for high rate data. 

Just to be doubly confusing, functions and G’s aren’t necessarily the same. There is 3G high rate data and 4G high rate data, and there is 4G voice and 3G voice. 

The communications protocols for voice on 3G on CDMA networks uses Qualcomm’s EVRC (Enhanced Variable Rate Coder) and on WCDMA networks is AMR (Adaptive Multi Rate) coding. The coding converts sound to data bits. Just to stay confusing, 4G voice, under the Voice over LTE (VoLTE) framework uses AMR also, but the rest of the voice protocol is very different than 3G. 

Data story is similar with 3G high rate data on 1X CDMA 3Gpp2 based networks is EVDO (now Rev A is most common) and on WCDMA 3GPP based networks is HSPA (now HSPA+ is becoming the most common.) For 4G we will only focus on LTE which happens to be 3GPP based.

There’s a lot of complexity in communicating the bits back and forth from the network when you compare 3G and 4G and CDMA 1xRTT with WCDMA/HSPA. Due to technical and cost constraints, most devices up to date have been either CDMA 3GPP2 capable or WCDMA 3Gpp capable. As an example, Qualcomm Gobi based devices have support for just about every situation in one component whereas Marvell only supports 3G WCDMA/HSPA and LTE.

A strong desire exists for every device to support every scenario, however the complexity and risks sort of dictated this approach of multiple networks, separate devices. See this seamless mobility chart, key point is you need both protocols, 3G and 4G for now.


Wireless mobile networks have had this multilayered architecture to support 3G circuit switched voice and high rate packet data at the same time for a while now. Adding in LTE is another layer of complexity that manifests itself as a battery and size constraint for today’s UE designs (more HW + more communicating layers in the devices), and in fact Steve Jobs specifically mentioned it as a barrier to LTE implementation in the iPhones.

UE Parallelism/simultaneous use

So now we are clear a device that has a single baseband processing path may only be on one network at a time. That was very long windup and I apologize. Back to the problem of the Verizon iPhone vs the ATT iPhone and voice and data simultaneously…

A mobile device that only supports a single network (voice or data) device will have to pause communicating with the data network if a voice call is to be made or received and vice-versa.  

The first generation of 3G/LTE capable devices have 2 physical components, a 3G path processor and a LTE path processor.  Qualcomm, TI, Marvell and others are beginning to ship components to enable the 2nd generation of LTE devices, those with 2 paths and shared silicon (fewer components.) The first devices are hitting the shelves. The benefits will be improvements to battery life and form factor, however neither will be as best they can be yet. Have a look at a slide from Qualcomm presentation comparing various architectures based on heat (energy waste) output. So it takes 2 radios to have a 3G and LTE flow from the device at the same time in order to support true simultaneous data and voice use.












The next step in device design will either be VoLTE and/or a software defined radio approach that allows more effective conservation of resources but that’s a topic for another day. Back to voice+data.



OK so the ability to make 3G voice calls and use data at the same time can be broken into smaller pieces.

  • For 3G 1X or 3GPP2 based networks like Sprint, Verizon, MetroPCS etc…, 1X (voice) + EVDO (data) is called SVDO. Some devices support this but most networks do not…As an example, the Verizon iPhone either communicates data or voice at one time.
  • For 3G WCDMA or 3GPP based networks, the voice and data bearers can be controlled from a single control point, (before HSPA it was on the same channel) therefore the voice and data can flow effectively in parallel. I won’t go deeper but this is the end effect although there are some finer points.
  • 4G LTE based networks need to have Simultaneous Voice and LTE (SVLTE) capability on both network and devices to operate in parallel.  It’s a specific function that allows better control of the voice and data over the networks. 

Today’s 3G + LTE networks carry voice over 3G networks as circuit switched voice. In a circuit switched paradigm, voice is carried in a point to point stream and requires real time connection between the two points, much like 2 tin cans with string, or a wired phone. Voice over packet, such as voice over IP networks use a connectionless paradigm, no open line is required. The world is starting to prefer it because this method also allows the use of the time in between the sound pulses to carry other data. Skype is and example of voice over packet (sound is quantized and sent over packets on the internet.) 

So the next iPhone launch with Verizon (3GPP2 based) will require specific upgraded network functionality like enhanced High Rate Packet Data (eHRPD) to be deployed as well as a multitasking OS, and multiple connectivity chipsets to enable simultaneous use whereas ATT (3GPP based) will have an easier time and only require the UE capabilities.

As of right now, the Qualcomm MSM9600 chipsets appear to support the SVLTE functionality and based on their use in The New iPad it appears Apple is headed down this path so it will be up to Verizon and others to deploy the necessary network upgrades.

Hope this helps.

Interesting slides on VoLTE….

Voice over LTE

LTE Benefits to the End User

Thought I would have some fun and go through the top 5 reasons the average consumer should adopt LTE. The point was to verify there were some end user benefits vs operators seeing all the benefits. I did my best to limit myself to today’s benefits, so there’s no HD Voice or global roaming etc in the list. See if you can think of better ones. Here are my top 5…Drum roll….

  1. Increased competition between carriers
  2. Supports ever growing Multi-mega pixel camera trend
  3. Safer to use at the sandwich shop than WiFi
  4. Low(est) mobile wireless latency
  5. Alternative to DSL at home
What? Here it is atom by atom.

1. Increased competition between carriers:  In the US, a less competitive wireless market, ATT, MetroPCS and Verizon already offer LTE, Clear, CSpire, Sprint, T Mobile, US Cellular are launching this year. I don’t like paying $25/GB/mo so I’m hoping the price competition will pressure down those prices. Yes supply and demand effects will have me using more and paying more, the low end is a mental barrier that needs to be crossed. Secondly, the increased competition with the identical services will result in greater focus in performance. The networks themselves will improve as a basis of competition further making end user experiences better.


2. Supports ever growing Multi-mega pixel camera trend: For this one , it’s bandwidth. Tip of the iceberg example, no way 3G is going support transporting your 17Mega pixel pictures of the puppy rolling over very quickly. LTE’s bandwidth will help out greatly here. Also, it looks like we are finally wanting to video call each other which is not very pleasant out on the road on 3G.


3. Safer to use at the sandwich shop than Wifi: Security of LTE vs WiFi is very deep and I won’t go into all of the nuances. Suffice it to say, at the lowest common denominator, it’s not free to begin stealing your data if on an LTE network. It takes significantly more effort than that. All that being said, I don’t want my instant messages to my wife on the internet. (yeah, ok, assume I have some end to end secure IM client.)


4. Low(set) mobile wireless latencyGaming. ‘Nuff said. Actually since the latency is so much lower than other wireless technologies, it’s going to make Push To X (PTx) services finally really usable. It also benefits chat and video calling a great deal. All of these apps are far more possible, pleasant etc on LTE than 3G or even WiFi under low loading in some cases.









5. Alternative to DSL at home:For this one  Tie it to your ‘stick it to the man’ strategy. Don’t know about you but it’s only recently I’ve had choices in wired networking. Another option never hurts when it comes to connectivity at home. More competition, and better pricing, better service as mentioned above.  

Thing about working in the industry is I have to focus on the customer and tell them what they need to know on the the other hand the thing with blogging is I get to rant. Well here is a rant about LTE….

 Is it just me or is there a disconnect between the direction the cellular operators see for us and where we would like to go? I was looking at some of the levels for LTE service here in the US and I guess I am just expecting something different than I am getting. Firstly, I do understand that LTE is a new technology and this handy Gartner Hype Cycle chart efficiently shows where my expectations should be.  Yes intuitively I understand that I am headed to the trough of disillusionment over my lack of high speed wireless connectivity, however in this chart all of these things pertain to how I perceive and use the service. This is clearly not a technology issue. What I have a problem with is how the market is providing the service.  Read Full Article →



Voice over LTE (VoLTE) is the next big thing. In fact, in 24 months, virtually all LTE enabled smart phones will support it. Curious?
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