More details on NTT Docomo's Xi Femtocell

Japanese operator, NTT Docomo recently published some more details about its Xi Femtocell service. The Femtocell is a dual mode LTE-WCDMA femtocell. WCDMA is mainly used as a CS Fallback option when used with LTE device. In this case if the WCDMA part stops working for some reason then depending on the macro availability, it may hand the UE back to Macro or just keep using the LTE only service.

I could not completely figure out but it also looks like the Femtocell operates in co-channel with the Macro. During the power on, SON algorithms device the codes, the power of the femtocell, etc.

The complete article is embedded below:

W-CDMA/LTE dual-mode Ultra-compact Base Station (Xi Femtocell) from Zahid Ghadialy

Enterprise Small Cells - Small Cell Forum Release Two

The long awaited "Release Two" from the Small Cell Forum is finally here.



Gordon Mansfield is explaining this Release two in the video above.

Small Cell Forum (SCF) also released a Small cell market update. As per the market report, as of October 2013, there were:

• 7.2 million residential femtocells deployed
• 168,000 indoor small cells deployed
• 2,700 outdoor small cells deployed

There is a good summary of this Release on ThinkSmallCell and TMN. Definitely worth a read.

There are a lot of documents released or revised as part of Release-2. You can access all the Enterprise related documents at http://www.scf.io/en/use_case_documents/Enterprise.php. You can also start with just the overview document at http://www.scf.io/en/documents/102_-_Release_Two_-_Enterprise_Overview.php

Finally, for more technical minded people, they can directly jump to the Enterprise small cell network architectures document at http://scf.io/en/documents/067_-_Enterprise_small_cell_network_architectures.php

LTE-U: First step towards 'Operator-neutral' Small Cells

3GPP member companies have decided to take the Small Cells vs WiFi fight back into the Wi-Fi camp by unveiling the initiative to have LTE in the unlicensed band (officially known as LTE-U but another interesting term uLTEA has been proposed unofficially too). 

Mike Roberts wrote an interesting post on ITM Blog:

Qualcomm has launched a radical initiative to deploy LTE Advanced in the unlicensed 5GHz band, which has traditionally been the preserve of Wi-Fi devices. If the initiative gains support, it could be a hammer blow to carrier Wi-Fi, though Qualcomm says it is still a strong supporter of all types of Wi-Fi, given its Qualcomm Atheros division, which is a leading producer of Wi-Fi chipsets. 

Qualcomm CEO Paul Jacobs unveiled the company’s initiative for LTE Advanced in unlicensed spectrum at its financial-analyst day in New York on Nov. 20. It was interesting timing, considering that the main annual carrier Wi-Fi event, the Wireless Broadband Alliance’s Wi-Fi Global Congress, was taking place on the same day on the other side of the world, in Beijing. 

The chipset giant followed the announcement by its CEO with detailed presentations on the initiative at Informa’s LTE North America event in Dallas on Nov. 21-22. The essence of Qualcomm’s proposal is that it is complicated to integrate LTE and Wi-Fi to create carrier Wi-Fi, so a better option could be to use LTE Advanced to extend LTE into unlicensed spectrum, thus eliminating the need for Wi-Fi in that context....So how does Qualcomm plan to square this circle and offer reliable mobile services in unreliable unlicensed spectrum? By using LTE Advanced to create a hybrid system operating in both licensed and unlicensed spectrum at the same time. Specifically, Qualcomm is proposing a system that uses the carrier-aggregation (CA) feature of LTE Advanced to aggregate licensed LTE spectrum with unlicensed spectrum in the 5GHz band. The unlicensed spectrum, which would be aggregated with licensed spectrum on the downlink only, would only be used for data services. The licensed spectrum would be used for uplink and downlink and would support network control as well as voice and data services. Given the power limits placed on devices using the unlicensed 5GHz band, uLTEA would be used mainly in small cells, similar to Wi-Fi.

'All about 4G' did a good quick write-up on this topic from standards perspective, as follows:

Qualcomm has recently floated the idea of deploying LTE in unlicensed bands, particularly focusing on the 5GHz band, which is currently used mostly for WiFi. According to a document (RP-131635) submitted to the upcoming 3GPP plenary meeting, the proposal is to deploy LTE as Supplemental Downlink (SDL) in 5725-5850 MHz in USA, with the PCell (Primary Cell) always operating on a carrier in a licensed band. Verizon has also submitted a Work Item Proposal (RP-131680) to to introduce the new band for SDL usage. There’s also a Study Item proposal from Ericsson (RP-131788) is the rapporteur to study the modifications necessary to the LTE radio.

One of the big issue (though small cell vendors often play it down) that has been delaying the rollout of Small Cells has been interference management in co-channel deployment cases. The operators are worried about ad-hoc small cells creating interference with the properly planned and optimized Macro cells (though in practice its not as bad as they think it is). With LTE-U, this issue can be put to rest.

I can see LTE-U, if adopted, can also help create new business models around Small cells. Neutral Small cells, deployed in the hotspots like stadiums, shopping malls, etc. can serve users of all networks. The signalling can take care of each user connecting to its own network using backhaul.

Femto as a Service (FaaS) and Small Cells as a Service (SCaaS) would probably become a common approach as there would be no concerns about which spectrum is being used. 

There would be a small concern about interference between Wi-Fi and Small cells. Most of the existing Wi-Fi and other devices that use unlicensed spectrum use the 2.4GHz band with a few using 5GHz band now. If LTE-U uses the 'Listen Before Talk' approach, other technologies can be enhanced to probably do the same. Another thing worth remembering is that there is nearly 300MHz of spectrum in 5GHz band available universally. In certain countries the available spectrum can be as much as 500MHz. This should be enough for LTE-U as well as other technologies in the unlicensed spectrum.

The complete Qualcomm presentation is embedded below and is available to download from here:

Wi-Fi as the preferred cellular access and barriers to roaming

Republic Wireless, a regional carrier in the USA is doing some interesting stuff with Wi-Fi and is possibly going to create some interesting challenges for established cellular carriers. An extract from a recent article in Washington post as follows:

Consider Republic Wireless, a Raleigh-based business that announced this month it would sell Motorola's new flagship phone, the Moto X. Republic enjoys all the traditional advantages of an MVNO — low capital expenditures on infrastructure and spectrum — but it's taken the additional step of cutting out 3G and 4G data use whenever it can. Technically, Republic operates on Sprint's network, but it's more appropriate to think of Sprint as a backup for when a call or message can't be completed over WiFi.

Yes, you read that right: WiFi. Republic's business depends on shunting all of your communications — data, voice, everything — onto the free stuff you get in your office or in coffee shops. What makes this beautiful is that whenever a Republic customer chooses to place a call over WiFi, that saves Republic money. As a result, Republic can offer a $5-a-month plan for unlimited talk, text and data. For another $5 a month, customers get access to Sprint's cellular network (minus 3G). Higher-tier plans provide 3G and 4G Internet on Sprint, though it's almost a joke to call them "higher-tier" when the most expensive plan tops out at just $40 a month. The tiered plan supersedes an old, $19-a-month all-you-can-eat plan.

"The crazy plans at $5 and $10 have never been tried," said CEO David Morken. "That's because we focus on unlicensed spectrum as the primary, and licensed spectrum as the secondary."

This approach can be quite disruptive for the MNO's. With NGH / HS2, soon MVNO's like republic wireless will be able to offer roaming on WiFi, thereby cutting the costs while not in the home market.

WBA released an Industry report recently (embedded below) which had some interesting findings.

Industry bodies, vendors and device manufacturers are working hard to get rid of some of these limitations and barriers. Once these limitations are gone, there is going to be a good business case for offering of global Wi-Fi roaming for example.

Another interesting question in the survey was what would be your preferred means of building Wi-Fi footprint. One of the answers is shown above, a similar question was asked in a webinar and posted in the 3G4G blog post here.

Finally, since the WBA report mentions about Wi-Fi and Small cells data offload, you may find a previous post of interest here.

The complete WBA report as follows:

Wireless Broadband Alliance Industry Report 2013: Global Trends in Public Wi-Fi from Zahid Ghadialy

SUPER cell, by SK Telecom (SKT)

This looks very interesting and similar to some other concepts that I have discussed on 3G4G blog. One of them is the Multi-stream Aggregation (MSA) that allows aggregation of data from different radio access technologies. Another is the Phantom Cell concept, proposed by NTT Docomo, where control plane is handles by one cell and data by another. Small cells would generally do only data or larger cells would do control plane. Of course you can have different combinations as can be seen in the picture above.

This also reminds me of the earlier post about Super Macros. Is this SUPER cell a Phase 2 of the Super Macro kind of architecture? Or is it just a future 5G concept? Please feel free to add your comments.

Here is the embed of their complete presentation:

[Sk telecom] network evolutionand emerging services for future mobile broadband pt final from Netmanias

What are Homespots?

Recently I got introduced to the term 'Homespots'. While I knew what they are, I wasn't aware there was a term for them

The slide above and below are from a recent webinar by Maravedis-Rethink (embedded at the end of the post)

In UK we have BT FON and Openzone which are both Wi-Fi hotspot services. Openzone is actually a hotspot deployed and maintained by them while FON is actually a Homespot, which uses spare capacity from the open Home Hubs deployed in the homes. BT has some details about it here.

Anyfi whitepaper shows (see above pic) some of the technical challenges that need to be kept in mind while deploying Homespots.

Anyway, here is complete presentation from the webinar mentioned above

Video Offload -Six trends you NEED to understand! from Zahid Ghadialy

KDDI Japan, Traffic Offloading Strategy

While going through some KDDI presentations, came across how they planned and perform Offloading. In fact, even before the deployment of LTE, they were aware that the network capacity would not be enough for the savvy Japanese mobile phone users. They had to start planning for how to offload the users as soon as possible. 

au Wi-Fi is their Wi-Fi offloading strategy where they make Wi-Fi hotspots available for the users. They even claim that with Wi-Fi on, the baattery life could be 1.5 times the normal 3G battery life.

UQ WiMAX is another KDDI company that allows users with compatible handsets to offload to WiMAX. KDDI have their own WiMAX branded services as well, see here.

Finally, with the LTE rollout they have different hierarchical cells available that the user could be moved to if one of the layers is congested. 

Small Cells and Wi-Fi in 3GPP Releases

Here is a quick chart of features of Small Cells and Wi-Fi introduced by 3GPP in different releases. Please feel free to suggest anything that has been missed out.

Optimizing Small Cells and the HetNets

Came across a whitepaper from JDSU, not so new but its got some interesting stuff. In an earlier post here, we saw the challenges for small cells deployment, the picture above shows another view.

Another interesting item is adding intelligence to small cells. This can mainly help by reducing the traffic back to the core. This also relies on predicting the user behaviour which could be a challenge in it self. There is a lot more interesting stuff in the paper, which is embedded below:

JDSU: Optimizing Small Cells and the Heterogeneous Network (HetNet) from Zahid Ghadialy

New opportunities in Carrier Wi-Fi & Wi-Fi offload

Interesting webinar from Maravedis-Rethink exploring the new opportunities with Carrier-WiFi and Offloading. Embedded below is the video and presentation:

Carrier Wi-Fi & Wi-Fi offload from Zahid Ghadialy

The right technology for different Enterprises

The enterprise deployments seem to be hotting up. Back in May, Telefonica O2, Germany, announced 'Signal Box', their enterprise femtocell based on UMTS to improve indoor coverage. Recently Vodafone in Netherlands announced that they are offering enterprise small cells from Spidercloud. There was an interesting article in Fierce Wireless about the enterprise small cells opportunity. The relevant part is reproduced below:

So it is perhaps no surprise that the industry has turned its attention to the enterprise segment, one which has less price-sensitive customers with higher demands for coverage, capacity and sophisticated mobile services. Enterprise small cells are much more in evidence, such as ip.access' nanoCell, which can be deployed in conjunction with Distributed Antenna Systems (DAS) in enterprise environments, and many vendors now focus on how to position small cells to penetrate this high-value segment. This is the new hot segment, opening up a rich service portfolio to offer to enterprise customers, a market that has been a tough nut to crack for mobile operators.
Combining enterprise small cells with network-based management applications potentially enables operators to add significant value to this segment by bringing new mobile services and features. These could include dedicated voice capacity, mobile unified communications, mobile call recording, local switching of voice traffic and context aware services, as well as the fast-developing field of network analytics.
However, there are also several key enterprise challenges that are significantly more complex than those found when offering femtocell services to consumers, such as managing inter-cell interactions, delivering consistent coverage over larger areas than a home or SOHO, as well as typically needing to support increased user numbers with higher user mobility. All of which means that as small cells become part of mobile operator strategies, there is a rising need for common guidelines and best practice, for products and deployment and Release Two provides an "all you need to know" guide to help operators deploy enterprise small cells. This follows on from Release One, a similar exercise centered on consumer femtocells, unveiled in February at Mobile World Congress. Release Three focuses on urban small cells and is scheduled for release at Mobile World Congress 2014.
Infonetics believes that deploying small cells within the enterprise segment represents a huge opportunity for mobile operators for several reasons:

• the mobile operator has the opportunity to increase indoor coverage within an enterprise campus, both indoors and outdoors;

• enterprise IT architects are seeking to move all personal communications services on to mobile devices and "unwire" their organizations, particularly as employers increasingly have BYOD policies;

• as they do so, there is a need to "mobilize" some of their existing communication services such as IP PBX, Centrex, IP VPN etc.; this also takes away the emphasis on "buying small cells" and places it on "improving/mobilizing communications" as the cost of those cells can be bundled with those services

• in deploying infrastructure within the enterprise premises, the operator has the chance to place "golden handcuffs" on the enterprise and pull them into an extended length of contract; one might argue that BYOD means that there is a need to support multiple mobile operators not just one selected by the enterprise, but in reality if one operator offers to provide small cell coverage, there is usually a positive migration to that network by employees (even if it is a case of BYO SIM);

• IT budgets are shrinking and there is increasing pressure on enterprises to outsource communications as they don't have the staff to deal with the complexity and rate of change, so there is the potential for operators to take on network operations for their high value customers

However, to date the enterprise has largely proven hard to target effectively. Traditionally this market segment has been underserved, as options such as DAS have only been available to larger scale enterprises due to the considerable costs involved. There are specific challenges of using DAS, which require a room in which to deploy a macro/pico BTS, and then the installation of industrial-grade coax to pipe the signal around the building, and sometimes requires an upgrade to the building's power. This is often invasive, expensive and time-consuming.

Recently I came across an interesting report on Enterprise small cells from Maravedis-Rethink which is embedded below:

Small Cells Inside the Enterprise - The “Who, What & Where” from Zahid Ghadialy

Super Macros and HetNets

The other day I read the following on Light Reading:

UK operator EE wants to turn its existing macro cell sites into "super macros," according to Andy Sutton, the carrier's principal network architect, speaking at the recent Base Station conference in London.

EE 's plan to super size its macro cell sites fits in to a broader Heterogeneous Network (HetNet) strategy for adding capacity and extending coverage. The operator rolled out the first LTE network in the UK last year, and has now covered 55 percent of the UK population and has 1 million 4G customers.

"Super macro is the first step toward building a HetNet,” said Sutton. “Evolving the macro is the most cost-optimized way to adding capacity into our networks."

But what makes a macro super?

According to Sutton, a super macro would typically have multiple radio access technologies (RAT), three-to-six base station sectors, and operate in multiple frequency bands using carrier aggregation techniques. It could be a standalone base station or a hub for subtended, smaller micro cells. He added that infrastructure sharing is vital to the strategy as well.

Once the operator has sufficiently beefed up its macro cell sites, then it can look to smaller cells to be deployed indoors and outdoors in hotspots or cell edge locations. Sutton described a small cell deployment as an "underlay" to the super macro.

The term super macro isn't exactly new, but the fact that operators are talking about it now indicates just how much more they are looking to do with their existing radio access network (RAN) infrastructure before introducing new small cells or while planning a small cell deployment.

"Within the super macro concept, there's quite a lot operators can do to improve performance," says Heavy Reading senior analyst Gabriel Brown.

Along with adding sectors, using more spectrum bands, or employing carrier aggregation, Brown also includes in the super macro concept using 4x4 and 8x8 MIMO, active antenna systems, vertical sectorization, or beamforming.

The advantage of improving macro sites is that many of the basic elements that go into the total cost of ownership of a cell site are already in place, such as power, real estate rental, and backhaul, according to Brown.

I remember the folks from Ericsson mentioning about Super macros but I had not given any thoughts to it. Well, I went back to see what they have been talking about and found this:

Since it was not very clear, I found some additional information from an NGMN presentation as follows:

In order to reduce UEs’ frequently handing over between neighboring cells when moving at high speed which results in voice service or data download breakouts in the railway/subway/highway scenario, different RUs in different sites using C-RAN architecture can cooperate with each other and many macro chain cells can be combined to a super macro cell. In this burst communication scenario, network performance has higher priority than network capacity.

So my suspicion is that Super macros would be ideally using C-RAN where it would be possible to combine what could be many macros into a 'super macro'.

If I start thinking about it, there can be additional uses of the super-macro:

1. Carrier aggregation - scenario 4 - see here. In Release-10 scenario 4 is not possible because of different timing advance requirements but this has been resolved in Rel-11. Super Macros can be useful in this scenario where small cells provide capacity, super macro provides coverage and reduces the need for constant handovers, etc.
2. NCT - related to the above - see here - again, smaller cells (metrocells/microcells) using NCT to provide capacity, super macro for coverage
3. Phantom Cell - see here - related to 1 and 2 above, super macro is the coverage, connectivity and mobility layer, small(er) cells are phantom cells that provide higher data rates. 

Anyway, a lot of information is pure speculation so feel free to add more info or correct my understanding.

Ericsson's Radio Dot System

Just come back from the SON conference, I noticed that Ericsson's dot system was discussed heavily on what it is and how its different from Alcatel-Lucent Light Radio and NSN's Liquid radio. Here is a bit of detail from the Ericsson press release:

Ericsson Radio Dot System is compact and offers flexible mounting. The device weighs 300 grams, is the result of two years of research and development, and incorporates 14 patents. It introduces a revolutionary antenna element, or "dot," which delivers mobile broadband access to users. Because of its convenient size, scalability, and compelling evolution path, this product caters to different kinds of users in medium to large indoor locations, and aims to address operators' needs of offering a complete indoor solution.

Dots are connected and powered via standard internet LAN cables (Category 5/6/7) to indoor radio units that link to a base station. Radio Dot System leverages the same industry-leading features found in Ericsson's macro base station. Deployments and upgrades are simple, addressing growing capacity and coverage requirements. Thus the users' experience is consistent wherever they go and the indoor network evolves in lockstep with the outdoor network. Ericsson Radio Dot System supports integration with Ericsson's carrier Wi-Fi portfolio enabling features such as real-time traffic steering to ensure the best user experience across both Wi-Fi and 3GPP networks. 

There was a bit more detail available from a discussion in the Linkedin HetNet group here. My edited version of the discussion:

***
A related patent by E///, on how they may be transporting digital I&Q (essentially CPRI) between RadioDot and IRU by introducing APL.


<The layers, from top to bottom, are CPRI layer, Adaptive Physical Layer (APL) and the Ethernet Physical (PHY) layer....

APL is a newly introduced layer for adapting and packetizing the data from CPRI layer to comply with the 10GbE PHY data frame format... >

http://www.sumobrain.com/patents/wipo/Remote-radio-data-transmission-over/WO2010145187.html
***

Based on my understanding, this is a standard Macro Cell with all functionality available from the day it is launched except that the PA+LNA+Filters+Antenna Panel (DOT) is extended remotely over Cat V cables. You can have multiple dots connected to a single cell based on the requirement as per DAS architecture. Now the Base Band Board and Radio Head may be centralized for the building. So this architecture may not really comply with C-RAN concept, so lots of features of C-RAN can't be supported with this. This is the very first step towards a centralized LTE DAS architecture for a big network. I think this is going to be a costly solution because of the architecture. One thing which is not known if this is based on SoC or the standard DSP FPGA based solution, because cost will be drastically low if it is based on SoC. Now it is interesting to see how the big carriers are taking this, since it is going to be launched in the second half od 2014, probably a very flexible hybrid DAS solution based on SOC will be available from many of the leading Small Cell Solution providers.
***

After my discussion with Ericsson executive, he explained the dots can be configured as different cells than the macro cell (in case the BBU is used for macro as well as indoor cells as posted in link to Ericsson document on page 11). 
***

I am very skeptical of this solution. It's a very nice marketing initiative - but I will be surprised if it achieves any serious market share. Mobile operators are mostly not capable of building the sort of networks that will require the dot - so deploying such a thing requires a change in mindset that is not easy to achieve. Secondly, the "dot" does nothing beyond what a $300 802.11n or 802.11ac Wi-Fi carrier class access point can deliver. And I'm sure $300 is not the Ericsson price for the dot. So I think the dot will find a very small market indeed. The much more interesting market is Wi-Fi offload at a fraction of the price. :-)
***

Embedded below is a presentation explaining the dot system:

The Statutory Hurdle in Small Cell Deployment

A presentation from MLL telecom in our recent event highlights the rules and the requirements from regulation during Small Cells deployments. The regulation hurdles are higher in Europe compared to most other parts due to strict requirements to make sure its not going to affect the character of an area and at the same time not to cause any damage to health and environment. Anyway, the complete presentation is embedded below:

Small Cell Deployment The Statutory Hurdle: Town & Country Planning (De-)Regulation of Small Cell Roll-out from Zahid Ghadialy

Small Cells to improve service in Disney parks

Slightly old news but I did hear Jim Parker, Senior Manager, Antenna Solutions group at AT&T talking about metrocells and their deployments in the Disney parks.

The original press release from July mentioned the following:

AT&T will add more than 25 distributed antenna systems in an effort to add capacity. It will also add more than 350 small cells, which extend the availability of the network. AT&T is adding 10 new cell sites across the Walt Disney World resort to boost coverage and capacity. And it will add nearly 50 repeaters to help improve coverage of the network.

Chris Hill, AT&T's senior vice president for advanced solutions, said that AT&T's efforts to improve coverage in an around Disney resorts is part of a bigger effort the company is making to add capacity and improve coverage in highly trafficked areas. He said that even though AT&T had decent network coverage already within the Disney parks, customers often experienced issues in some buildings or in remote reaches of the resorts.

"The macro cell sites can only cover so much," he said. "So you need to go to small cells to really get everywhere you need to be and to provide the capacity you need in areas with a high density of people."

Hill said the idea of creating smaller cell sites that reuse existing licensed spectrum is a big trend among all wireless carriers right now. And he said, AT&T is deploying this small cell technology in several cities as well as other areas where large numbers of people gather, such as stadiums and arenas.

"We are deploying this technology widely across metro areas to increase density of our coverage," he said. "And it's not just us. There's a big wave of small cell deployments where tens of thousands of these access points are being deployed all over the place."

Cooperation with Disney is a key element in this deployment since the small cell technology requires that AT&T place access points on the Disney property. The footprint of the access points is very small. They typically look like large access points used for Wi-Fi. Hill said they can be easily disguised to fit in with the surroundings.

One of the other interesting thing (if I understood correctly) that Jim mentioned is that they are deploying Neutral host DAS solution that is open to all operators, whoever is interested in. They are also going to provide three separate charging points that will allow anyone to charge their phones (free of charge, I guess). It is nevertheless an interesting project that should prove HetNet concept. 

Wi-Fi and Cellular Data - Two sides of the same coin?

Going through a presentation from Small Cells World Summit, Analysis Mason argues that all WiFi activity is not just offload / substitution of cellular data but to a lot of extent its addition too. I completely agree as I think that once users get used to using data on their devices, they are more comfortable in using much more data over WiFi. Of course here I am assuming carrier or public WiFi rather than what is privately used at home or in the office.

To a lot of extent this use of data is encouraged by the operators and the newer and more efficient technologies. Once a 100MB data cap was more than enough for most users while now, most users struggle with 1GB of data caps. WiFi is always an alternative, especially if the data usage is not counted in the allowance or included at a reduced rate.



An article published today, highlights this same points in case of students. Here is an extract from the article, which is available here in entirety:

Data captured by Actix shows that an average university campus will exhibit a daily population of up to 25,000 students who use mobile phones as their social hub.

While this population is much lower than city transport hubs and central business districts, it generates some of the highest levels of daily data and voice traffic.

A university campus will generate 60% more calls per person per day, and 388% more data per person per day compared to traffic in a business district.

Universities also have the highest levels of data upload, accounting for 30% of all data traffic at the location.

Neil Coleman, Director of Global Marketing at Actix, says: “While the ‘more for less’ mentality is hardly new, students as early adopters and power users of mobile provide an important gauge of future trends. Network operators need to accommodate these evolving attitudes to mobile use if they are to continue to deliver effective, profitable networks.”

Actix estimates the demand for data sessions on mobile networks will have increased by a factor of ten by 2015.

To accommodate their increasing data demands, students make greater effort to use Wi-Fi to secure the most data at the lowest cost.

While imperfect in terms of a seamless experience, Wi-Fi is perceived by students to be worthwhile when trying to keep costs down.

However this behaviour has unwelcome implications for mobile operators as they lose control of the customer experience and revenue opportunities when students hop off the network.

“Operators need to get to grips with Wi-Fi, either by finding a way to monetize it or by encouraging subscribers to stay on the mobile network with better quality service and realistic tariffs,” says Coleman. “With heavy uploads and two-way social traffic dominating the modern campus, operators have to prepare for an increasingly social customer base.”

The presentation from Analysis Mason is embedded below:

Wi-Fi and Cellular Data – Two sides of the same coin? from Zahid Ghadialy

Related post:

• The growing synergy between Small Cells and Wi-Fi
• M2M, Cellular and Small Cells

Building a Sustainable HetNet - Telus, Canada

Came across this interesting presentation from the LTE World Summit 2013, one from Telus in Canada. The presentation is embedded below but here are couple of things that caught my attention:

One of the issues which is now becoming universal is the need to negotiate with the municipalities and local councils for the right to lamp posts and other street furniture. I blogged this earlier as well with regards to a presentation by EE here. This also encourages for a third party to provide small cells hosting as a service (SCaaS)

Another issue generally faced in case of Hetnets is the Interference management in case of shared carrier. Looks like they may be using a proprietary approach for co-channel deployment and similar approaches are possible with basic SON presence in the network.

Anyway, the complete presentation below:

Building a Sustainable HetNet from Zahid Ghadialy

The growing synergy between Small Cells and Wi-Fi

The growing synergy between Small Cells and Wi-Fi from Zahid Ghadialy

Small Cell Backhaul: Industry Trends and Market Overview - Slidedeck

Very good overview of Small Cells backhaul by Monica Paolini, Lance Hiley and Frank Rayal

Enterprise Small Cell Architectures

Deployment in enterprise is a challenging task for the operators but it has many benefits hence this is one of the areas they have been working very hard to get it right.
Release 2 from the Small Cells Forum, later this year will provide more useful insights into deployment of Enterprise Small Cells or Femtocells.

One such challenge for Enterprise small cells is the architecture for the enterprise deployments. Handovers play a big part and special care has to be taken to make sure they are seamless with little or no break during handovers.

Embedded below is a webinar from ThinkSmallCell from not so long back which deals and explains the issues. The last slide is the video of the webinar, in case you have enough patience to go through it. Finally, you can also download the whitepaper from Spidercloud on this topic here.

China Mobile's Nanocell

China Mobile prefers to call its Small Cell, Nanocell. I found an interesting summary on this topic from Rupert Baines in the OSP Magazine, some of this information is copied below.

Nanocell is defined by the China Mobile Research Institute (CMRI) as follows: “An integrated Small cell supporting GSM / TD-SCDMA / TD-LTE standards and WLAN (WiFi) solutions. With the key feature of supporting both wireless network and WLAN (WiFi) services, it can be deployed in enterprise, home and high capacity hotspot locations. It also uses standard broadband connection as a low-cost network backhaul, hence reducing deployment and maintenance cost while providing advanced and reliable security features.”

Nanocells, provide mobile coverage to a limited area as well as integrating carrier grade WLAN access points. They are often used to add network capacity in areas with very dense data usage. In some respects they are the next iteration in small-cell evolution.

Although in theory a nanocell could have a range as large as 2km, in most situations it will be less than that: perhaps 100m-500m. As such, a nanocell allows for deployment in locations that are expected to handle more phone usage than usual, for example during a sporting event or concert.

In September 2012, in a pioneering program to develop China’s mobile infrastructure, Mindspeed, the manufacturer of semiconductors for small cell base stations, signed a memorandum of understanding with China Mobile Research Institute (CMRI) in Beijing to contribute to the rapid build-out of China Mobile’s heterogeneous network (HetNet).

A HetNet is constructed with layers of small and large cells including nanocells. These cells will be able to self-organize seamlessly providing a higher quality and consistent connection to the network for users. The aim of this collaboration is to accelerate the field trial of TD-LTE small cell systems across the China Mobile Communications Corporation’s (CMCC’s) network in China.

As noted, CMRI’s definition of nanocell could be described as “small cell 2.0”. There are various architectural enhancements, but 2 in particular are worth describing.

CMRI Enhancement #1 is the integration with Wi-Fi. Some people naively view small cells and Wi-Fi as competitors. But a more sensible approach is to combine them, to take advantage of economies (single power supply, shared backhaul, cheaper provision and OpEx) and to use synergies in the  bearers (for example, handing off traffic between the 2, taking advantage of the extra capacity
of Wi-Fi with the longer range and better QoS from cellular). The Small Cell Forum has been working on this, and it is a key part of CMRI’s nanocell.

CMRI Enhancement #2 is multi-mode. One aspect of a nanocell, which is important to most carriers, is supporting several cellular standards in one node. Much of the cost is per element (siting, installation, OAMP, power, backhaul) so it makes obvious sense to combine them to share those costs and make the best use of the spectrum.

China Mobile is unusual in its cellular technologies. In common with most of the world it has GSM as 2G, but for 3G it uses TD-SCDMA (standardized by 3GPP and a variant on the commoner WCDMA). For 4G, it uses LTE but the TDD flavor (TD-LTE). This is not yet widespread, although estimates are that between 20%-40% of all LTE will ultimately use it. The CMRI nanocell must support these technologies.

Things have progressed well and in the recent Small Cells World Summit 2013, CMRI showed their enterprise deployments that are being tested.

A presentation from the WiFi global congress is embedded below and gives more detailed idea about the Nanocell.

Introduction of Nanocell - China Mobile from Zahid Ghadialy

WiFi & Cellular: True Love or Arranged Marriage?

An interesting video of the presentation by Nick Johnson from IP Access which he gave in the LTE World Summit 2013



You may also be interested in couple of related blog posts from the 3G4G blog:

• Wi-Fi & Packet Core (EPC) Integration
• What's next with 802.11!
• Four Options for Traffic Offloading
• Cellular-Wi-Fi Integration - technology and standardization roadmap
• 802.11u, Passpoint and Hotspot 2.0 (HS 2.0)

SK Telecom: Commercial deployment of LTE Femto cell

SK Telecom does not fail to impress with their aggressive roll-outs and impressive solutions to challenging problems. One such presentation from the Small Cells World Summit 2013 in London is embedded as follows:

Commercial deployment of lte femto cell with the innovative technologies and the roadmap from Zahid Ghadialy

Another presentation from late last year is available here.

Satellite Backhaul for Rural Small Cells

 A typical problem with the rural small cells is how to power and backhaul them. Power issue can be solved using Solar cells, wind turbines, etc. and generally a combination of them as a failsafe mechanism but what about the backhaul.

DSL is generally not available and Microwave links maybe difficult to acheive. How about Satellite backhaul?

iDirect have an analysis on the business case of using Satellite for backhaul which is embedded below:

Small Cells and Satellite from Zahid Ghadialy

An Informa report titled "Satellite backhaul for rural small cells" is also available on Slideshare here.

Site Selection - Nice animation by Alcatel-Lucent

See Also:

• The biggest challenge to Small Cells deployment

Interference in 3G Hetnets in case of shared carrier

We had a discussion earlier on 'dedicated v/s shared' carrier here. This post is just re-iterating the fact that while in case of LTE, there are advanced techniques like eICIC to manage interference (see 3G4G blog here), in case of 3G there are no standard techniques to manage the interference in case of shared carrier.

A recent presentation from ZTE in one of the conferences explains this point further that has been reproduced below for reference:

While I think SON can help in certain situations in case of 3G, the chances of coverage black holes are very high which can lead to radio link failures in ongoing calls. As such, the operator has to be absolutely sure where a small cell will be placed in a shared carrier situation for sake of maintaining a good macro coverage. 

Small Cells in LTE - 3GPP Rel-8 to Rel-12

A simple picture showing the Small Cells support in different 3GPP releases. For more details refer to the 3G4G blog here.

AT&T Experience: Small Cells in the office

From a presentation by Gordon Mansfield, in the Small Cells World Summit 2013.

What do the customers think?

“The Metrocell is working very well, we’ve seen significant improvements with data connection and speed which was our biggest issue before installation. Voice also seems to be working well.”

“The individuals within the office have seen a stronger signal and are able to make and receive calls in areas that they couldn’t before.”

“The new system seems to be working – my primary benchmark is whether or not I experience dropped calls …. I am not. In the past I received a voice mail notice but the phone never rang to give me an opportunity to answer it now all calls are coming through.”