Currently viewing the tag: "eNB"

Update: Forgot that Artiza Networks has a nice and clean version. Mine looks like a messy room in comparison. :) See bottom.

Just sharing this, it’s something I did before and forgot where I used it. I think I summarized some details, such as the millions of IMS pieces but broke out important functions such as HSGW vs PDSN and IWS etc for clarity. Enjoy…

The Network Mona Lisa


This version was created by Artiza Networks…

March 21st FCC kicked off an industry discussion with their FCC Docket No. 12-69

Promoting Interoperability in the 700 MHz Commercial Spectrum

Last Friday, (1st of June), Qualcomm shoots over some comments to the FCC in response. Specifically, a document titled:

Promoting Interoperability in the 700 MHz Commercial Spectrum

Interoperability of Mobile User Equipment
Across Paired Commercial Spectrum Blocks in the 700 MHz Band

12-69 06-01-2012 QUALCOMM Incorporated 7021921420

So normally I see things like this come and go and I don’t utter a word, however I would like to point out a few things about Qualcomm’s position that I feel like should be made more clear.

Below is a diagram of the lower 700MHz spectrum. A key problem for everyone today is there are DTV broadcasts in many urban areas with extremely high power transmitters. The current FCC requirements allow DTV stations on Channel 50 and 51 to spew interference into the lower portions of the 700MHz spectrum (See Channel A, B and C.) Furthermore, there are 2 blocks, the D and E block in the lower 700MHz that also allow high power (think 50KW of RF power) to be broadcast. For LTE this could be a huge issue to both devices and base stations. Fundamentally, this is an unfair situation to those that purchased spectrum in the lower 700MHz areas and ultimately a problem for end users due to the limitations this places on what we can or can’t do now.

OK so Qualcomm didn’t create this problem but they are aware of it as they have been working on providing components to handset OEMs that utilize this spectrum. So they are trying to facilitate the use of multiple radio bands into the devices we love so dearly but it’s complicated. See their list of spectrum’s they are interesting in building to:

  • 700 MHz 3GPP bands (Band Classes 12, 13, 14, 17);
  • 850 MHz cellular band (Band Class 5);
  • Original PCS band (Band Class 2);
  • PCS Block G (Band Class 25);
  • AWS-1 band (Band Class 4);
  • Potential AWS-4 band (Band Class 23);
  • Original 800 MHz iDEN band (Band Class 26); and
  • BRS band (Band Class 41). 
So Band 12 is the original band plan, that is channels A, B and C of lower 700MHz that 3GPP put into their specification to allow the use of this portion of the spectrum. ATT later came back and requested/received a different plan. The just happened to purchase mostly B and C channels in the auctions, so their proposal was to create a band around B and C called Band 17. The 3GPP approved it so it’s part of the build specifications in the devices. Unfortunately it’s not fashionable to support Band 17 and Band 12. Qualcomm’s document to the FCC explains their logic on why this can’t happen. Therefore, components from Qualcomm today support Lower 700MHz Band 17 (ATT), Upper 700MHz (VZW) and now Band 25 (Sprint), with AWS support (Band 4) for others like Metro etc… If you are not ATT, VZW, Sprint, or AWS spectrum holder, you are not supported for LTE essentially.
Qualcomm developed more stringent filter requirements for Band 17 than Band 12, partially by utilizing the Channel A/Band 12 as a guard band of 6MHz, but there is more to it than just that. 
Their justification looks like this:
Qualcomm’s tests and analyses demonstrate that consumer devices operating on the Lower B and/or C blocks using the Band 12 filter will suffer harmful interference from E Block and Channel 51 signals, while the Band 17 filter provides these devices with an effective defense. More specifically, these comments will show that without the Band 17 filter:
  • High-power E Block signals would cause blocking interference to consumer devices seeking to receive a 5 MHz signal on the B Block or a 10 MHz signal on the B and C Blocks;
  • High-power E Block signals would cause intermodulation interference to consumer devices seeking to receive a 5 MHz signal on the B or C Block or a 10 MHz signal on the B and C Block; and
  • Channel 51 television signals would cause reverse intermodulation interference to consumer devices seeking to receive a 5 MHz signal on the C Block or a 10 MHz signal on the B and C Blocks.

…blah blah…

In fact, Qualcomm’s innovations and ongoing work with carriers and manufacturers demonstrate that there is no need for any FCC mandate.7 Because of the difficult interference challenges described herein, the fact that existing technology does not offer a solution to these challenges, and Qualcomm’s ongoing innovation and collaboration with all carriers and manufacturers, the Commission should not require mobile equipment to be capable of operating over all paired commercial spectrum blocks in the Lower 700 MHz band

In reviewing their document it’s clear that they are protecting their interests, that is they are developing and have been shipping products around Band 17 and Band 13, where their orders have been coming from. I read it as they (QCOM) are not interested in the 700MHz Band 12 spectrum holder issues as much since these smaller interests represent a greater deal of complexity and will have less payback than serving the larger operators. The issue they hold up as the big fish is the fact a large signal from Channel 51 or D/E block causes blocking and IM at the device receivers.

Sooo naturally

 part of the American experience (IMHO) is the fight for the little guy. If Qualcomm is allowed to ignore Band 12 issues and only sell to the big guys then big business wins and the little guy loses. 

It doesn’t have to be this way, there is a way to get what you want but some things will have to change. 

Let me take a moment to crow, and eat crow. I wrote a series of posts deriding Apple for its design choices regarding the Qualcomm transceivers. I only went off of publicly available information to keep everything on the up and up. 

Apple, I’m sorry for putting it all on you. It wasn’t all your fault. My last post I did say you needed to get off your duff and fight for the little guy by making your own transceiver and or doing some band stitching solutions but it’s not all your fault.
My original Posts:

On the other hand, I was right about everything I said in the corrections on the Qualcomm parts. My assertions are backed up in Qualcomm’s document. The reason I say that is because this story is possible to resolve amicably and my assumptions are built on some truths.

Key point is new components such as Qualcomm’s WTR1605L make Band 12 deployment possible, just not supported without changes to the propagation environment of the broadcasters thanks to Qualcomm not wanting to go any further on the solution development.


  1. FCC doesn’t need to mandate the world to use Qualcomm’s products, much less the WTR1605L, the MDM9615/MFM8930 etc… There’s already a huge challenge getting multiple suppliers in the space and layers and layers IPR issues that haven’t even been made public yet….
  2. The rules on the side skirts of the Channel 51 and D and E block spectrum holders is causing harm to a greater number of people than changes to these rules would. Make the roll off’s sharp such that interference is minimized. Be more fair and only make it an optional mitigation to be whipped out in case an operator actually wants to deploy in the A, B or C blocks (Band 12) and not just for Band 17.
  3. Qualcomm could feel free to improve the Band 12 filter.
  4. Baseband interference cancellation would be a good part of a solution too.
  5. Utilize a small cell strategy to target users very effectively. It’s one thing dealing with interference from a 1000′ tower to the users served by your 200′ tower and another when the device and base station are within 100 meters of each other. I can help you do this if you don’t know how to make it happen.
  6. Lower 700MHz spectrum holders can consider a fixed deployment instead of mobile. It’s less difficult to null out interferers.
  7. If all else fails, just contact me directly. I will sell you TX filters to reduce the transmission of the interference and help you work it out with the broadcasters to boot.

  At the end of the day, it’s up to the little guy to fight the power. People need to voice their opinions on this matter. Do you want better LTE data coverage? Do you want more companies to be able to offer LTE? More devices? Are you completely confident that Verizon and ATT will pass any device savings on to you that they could get from locking out variations?

Contact the FCC and let them know what you think.


BTW, Mariam Sorond, VP of Technology Development at DISH networks states that TX filters are sufficient to allow normal operations and no FCC rule changes like reducing TX power of D/E block (DISH broadcast) is required…. See her response.;jsessionid=f796PTRD1w7bWhL1w1BnJdbpT1jT52XDGhMGQzMqsGvb0QMQxlGj!-1221852939!-1969853125?id=7021921464

 Information is the key driver in business decisions (other than gut feelings for some) and also the means to which you can assure that you will not be annihilated without warning. Our ancestors worked hard and often gave their lives to obtain it but this is the information age and things are much more straightforward. Finding out more is a few keystrokes away. (Can you tell I am on a research project at the moment?) Some good recent examples: 

Firstly there is an updated report from EJL Wireless Research. It’s The Global Microcell Base Station Market Analysis and Forecast, 2011-2016 . The report is now very focused on macrocells and WiFi so ADD readers like me can get we what we need and go. Major sections are the market forecast,  global market share and then the vendors. There’s some interesting ways they look at the marketplace that are fairly helpful and interesting. Their focus:

This research segment focuses on market trends regarding base station cabinets and BTS radio transceiver shipments including remote radio head technologies. The wireless technologies covered within the research includeBTS Transceivers

Circles GSM/GPRS
Circles EDGE
Circles CDMA 1xRTT
Circles W-CDMA
Circles CDMA EVDO Rev. 0
Circles CDMA EVDO Rev. A
Circles CDMA EVDO Rev. B
Circles HSPA
Circles HSPA+
Circles LTE

The reports listed in this section focus on unit volume shipments of the following products:

Circles BTS Cabinets (BTS)
Circles BTS Transceivers (TRx)
Circles Baseband Units (BBU)
Circles Remote Radio Heads (RRH) / Remote Radio Units (RRU)

Next, Market Publishers,  have unleashed their report, Public Safety LTE: A Global Assessment of Market Size, Technology, Vendor Trends and Spectrum Allocation 2012 – 2016 on humanity. This $1,995 report has some nuggets such as:

  • Over the next five years, the Public Safety LTE will grow at a CAGR of 90 % accounting for over $ 6 Billion in revenue by 2016, up from $ 240 Million in 2011.
  • Operator service revenues will constitute a vast majority of the revenue, followed by managed services and integration, representing a lucrative opportunity for vendors and system integrators to build, own and operate Public Safety LTE networks.
  • Europe will lag behind Middle East, Asia Pacific and Latin America in the early adoption of Public Safety LTE technology due to stringent spectrum regulation policies. A number of Public Safety LTE trials are already underway in these regions
Report Benefits:

  • Global Spectrum Allocation for Public Safety LTE: A global assessment of spectrum allocation and funding for Public Safety LTE deployments, based on input from regional regulatory authorities.
  • Global Public Safety LTE Market Size, Contracts & Trials: A global review of the worldwide Public Safety LTE market including assessment of revenue share by market segment (infrastructure sales, services, user device sales, etc), and a review of global contracts and trial engagements.
  • RAN Sharing and Roaming: The term “RAN sharing” refers to sharing of actual eNodeBs. As part of this arrangement, each operator accesses the shared RAN with its own EPC. Vendors are also considering the implementation of Inter-PLMN handover (as opposed to roaming) and then for LTE Commercial carriers to deploy Policies for Service Level Agreements that include Priority Access (Access Class Barring, Preemption and ARP) and QoS/ QCI assignment for default and dedicated bearers. The report assesses in detail how many of vendors and commercial carriers will support RAN sharing, roaming and inter-PLMN handovers which will be key factors towards the adoption of commercial LTE RANs for Public Safety applications.
  • Global QoS Requirements for Public Safety LTE Communications: A detailed assessment of global requirements for Priority access and High QoS for Public Safety subscribers, for shared commercial LTE networks, while they roam on to Commercial Networks.
  • Public Safety LTE Devices and End User Applications: An assessment of device usability characteristics, Multi-Radio LTE/LMR interoperability technology, Software and Applications (VoLTE, PTT over LTE, IMS, IP).
  • Vendor Trends and Roadmaps: A detailed assessment of solution portfolios and roadmaps for major infrastructure/ device vendors and system integrators
  • LTE-Advanced Support for Heterogeneous Commercial/LMR Networks: In-depth assessment of the LTE Advanced standard and technologies and spectrum planning for Fixed/Nomadic based Pico Cells/Femto Cells and mobile base stations (e.g. LTE Cell on Wheels (CoW)) and proximity based services such as Direct Mode Operation (DMO) in LMR systems, which have broad implications for the adoption of Public Safety LTE services.
  • LTE based Public Safety Tactical Systems and Military Applications: Detailed market assessment of LTE based Public Safety Tactical Systems such as CoW, Cell over Light Trucks (COLTs) and Military Applications for LTE.
So pick up these reports and expand your horizons. 

Airspan announced the release of a pretty good piece of technology for the LTE network deployment puzzle a few days ago, their Air4G. The key things here are that it is a physically small outdoor package, capable of both WiMAX and LTE. The primary thing that caught my eye was as an LTE eNB it features 2×2 MIMO (Single User [SU] and Multi User [MU]!), built in 2x 40dBm TX power, support for 700MHz and the ability to connect a Remote Radio Head (RRH) with a CPRI connection for more RF power! Arghh!  Overall if they can reasonably offer these, make the sale and provide decent support for these boxes, this should be a hit for them.

Links: Airspan 

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Design Art Networks has released a 40nm SoC that is very respectable in terms of specifications.  It is Release 10 (LTE Advanced) ready and only consumes 8W at full power, supporting up to  80MHz aggregate spectrum, and 16TX + 16RX paths (= 4 sectors of 4×4 MIMO). If the price is right, beware the onslaught of highly capable, low profile, base stations!

In its full glory following break.

Links: Design Art Networks, Business Wire

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So, as a follow up to our earlier story on SkyTerra-1.

Launch took place November 14, 2010 12:29 EST; 23:29 local time – Baikonur, Kazakhstan

Haven’t got any indications if the startup was successful. Like I said before, if looking for volunteers to do the initial acceptance and optimization, count me in. :)

Checking out SkyTerra Mission Control (ILS), looks like we’re really close to LightSquared’s Birthday. For those unfamiliar, SkyTerra-1 is a satellite manufactured by Boeing that is one of the largest ever launched, and will have duties as LightSquared’s space based LTE coverage for the continental United States, Canada, Alaska, Hawaii, Puerto Rico, the Virgin Islands, Mexico and the Caribbean. SkyTerra-1 will hover in a GeoStationary Orbit around 22K Feet at 101deg W, featuring  a 22m L-Band primary reflector (Antenna) with 11.9KW of TX power and support for 500 spot beams. The expected average throughput when outside is around 300-400kbps, so I guess that’s 11.9KW of single transmit (not MIMO) path power. At $400M a satellite plus the OPEX,  MIMO or TX diversity was probably too much expense to be an option. Well looks like November 14th will be the big day if all goes well for the ILS guys at the launch pad. After that there are 9 hours and 14 minutes of nail biting for the LightSquared folks. I volunteer to do the initial optimization!

Source: Boeing,,, and IDG News Service/Computerworld for the initial report

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Small Cells

Small Cells

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Public Safety

Public Safety

LTE is and ideal technology for Public Safety use. See Why.