Deutsche Telekom's Hydrogen-Powered Mini-Masts

Earlier in the year we wrote about Deutsche Telekom's Mini-Mast a.k.a. “Cell Tower To Go”.  Last year, DT set a new benchmark in sustainable technology with the deployment of hydrogen-powered antennas at the Nibirii Festival in Germany. This initiative replaced the traditional diesel generators with hydrogen fuel cells to provide eco-friendly energy for mobile base stations. The hydrogen is sourced in a CO₂-neutral process, marking a significant step towards green innovation.

For anyone who doesn't understand what hydrogen fuel cell is, this video has a good explanation.

At the festival, a hydrogen-powered mast supported 30,000 attendees with seamless LTE and 5G connectivity. The fuel cells, developed by SFC Energy, ensured reliable, uninterrupted service for 28 days, showcasing their potential for large events, emergencies, and remote areas. This shift underscores Deutsche Telekom's commitment to combining sustainability with technological advancements.

Additionally, compact mobile masts and stage-mounted small cells enhanced coverage and user experience. These innovations promise to redefine mobile connectivity, emphasizing rapid deployment and reduced environmental impact.

You can read the full story here.

Related Posts: 

• Telecoms Infrastructure Blog: Deutsche Telekom's Mini-Mast a.k.a. “Cell Tower To Go”
• Connectivity Technology Blog: Deutsche Telekom Demonstrates 12 Gbps on 5G Using 6 GHz Band
• Telecoms Infrastructure Blog: Deutsche Telekom 5G Small Cells in Phone Boxes
• Private Networks Technology Blog: Deutsche Telekom Deploys 5G Campus Network in Port of Duisburg
• Telecoms Infrastructure Blog: Omniflow Smart Street Lighting for 5G and IoT
• Telecoms Infrastructure Blog: Deutsche Telekom Launches Indoor Booster 5G Repeater
• Telecoms Infrastructure Blog: FC Bayern and Deutsche Telekom bring 5G to the Allianz Arena in Munich, Germany
• Operator Watch Blog: Deutsche Telekom's 'Tech Grounds' 2021
• Connectivity Technology Blog: Deutsche Bahn to get Seamless Mobile Network Along all Tracks
• Connectivity Technology Blog: 4G/5G Campus Networks and their Challenges 

Impact of Small Cells on Key Enterprise Markets

I missed the last CW (Cambridge Wireless) Small Cells event 'Are small cells ready for private LTE primetime in the lead-up to 5G?'.

Some excellent presentations at Cambridge Wireless Small Cell SIg today. This one from Ian Taylor of Quortus #CWSmallCell pic.twitter.com/SamiUIQWaP

— thinksmallcell (@thinksmallcell) April 2, 2019

From the CW website:

The limited progress towards excellent in-building cellular coverage is well-attested, and in many enterprise and industrial sectors, this is not just frustrating, but has a tangible impact on productivity and agility. In a wide range of industries, from transport to logistics to healthcare, there is pent-up demand for highly reliable, highly secure cellular connectivity, which often needs linking with localised applications and data.

That demand is only growing even more with the advent of IoT applications and edge computing. This is a huge opportunity for small cells, even before 5G, but these sectors cannot all be served by one generic network. Each has its own particular requirements, which need to be well understood by suppliers and partners, so that the deployment can be carefully aligned to business and performance objectives.

Excellent mobile connectivity indoors and out is the baseline requirement – each sector has its own additional needs, which will help to make the business case add up. For some, low latency may be important, for others, massive device density or enhanced security. All of these can be delivered optimally by small cells, but the design of the network, and the business model to deploy it – e.g. neutral host or private network – must be tailored to the enterprise, if users and suppliers are both to achieve the best ROI.

This event focuses on the real-world issues needed for the success of small cells in the emerging private LTE market.

The presentations are available for a limited time for non-CW members here.

The following presentations are available:

• 'Is private LTE disruptive' by Ian Taylor, Quortus [PDF]
• 'Small cells in private networks: An Overview' by Caroline Gabriel, Rethink Technology Research [PDF]
• 'Bringing connectivity to a mechanical test centre' by Peter Stoker, AutoAir [PDF]
• 'Private Networks for Critical Comms & IoT' by Tadhg Kenny, Druid Software Ltd [PDF]
• 'Business ready applications, not the connectivity solution, will be the driver for private networks' by David Rose, Veea Systems Ltd [PDF]

Related Posts:

• The 3G4G blog: Non-public networks (NPN) - Private Networks by another name

NTT Docomo's Underground LTE Small Cells with possibility to deploy 5G in future

NTT Docomo has announced that they have developed a prototype of manhole type base station for the first time in Japan. They will be used in locations where there is no other infrastructure available in vicinity to host base stations. The antenna is installed at a depth of 10 cm under the ground, with a fiber connection to the radio equipment and the power supply are drawn from the ground by the underground buried piping. The service area is about 90 m radius. 

Based on this, I am not sure if this is a complete small cell or just a remote radio head. I am inclined to think that this is a complete base station as its a standard LTE base station as per the specifications.

Manhole type base station specification (Sapporo verification station)

method	FDD-LTE
frequency	1.5 GHz band (BAND 21)
Bandwidth	15 MHz
MIMO compatible	2 × 2 MIMO
Downlink modulation scheme	256 QAM
Maximum Throughput	DL: 150 Mbps / UL: 37.5 Mbps
Size (buried part)	70 cm × 70 cm × 70 cm
Device size	About 29 cm × about 17 cm × about 7.5 cm
weight	Approximately 15 kg

Specification of manhole cover (Sapporo Verification Bureau)

size	Diameter 64.8 cm · thickness 5 cm
weight	Approximately 27 kg
Load bearing capacity	25 tons

The output power is not specified but base stations can easily fit within 15 kgs.

I have written about underground small cell here and here, which was about Swisscom, Ericsson & Kathrein trying it in Switzerland. I have also written about how the Japanese operator KDDI is trying to cover similar locations using lamp posts here. Its good to see Docomo trying something new.

As per the announcement, DoCoMo will work to improve the communication environment to areas where it was difficult to establish a base station, aiming for full-scale operation within the year 2018, and will continue to consider the application of future technologies to 5G in parallel.

From what I have heard, some antenna manufacturers are working on trying to convert the manhole cover in to an antenna. Its going to be a big challenge though.

Related Posts:

• Telecoms Infrastructure Blog: KDDI to test 5G with base stations built in Street Lights
• Telecoms Infrastructure Blog: Underground Small Cells
• Telecoms Infrastructure Blog: Small Cells & Wi-Fi in the pavements & roads
• Small Cells, Macrocells, Backhaul, Infrastructure and other connectivity solutions from #MWC18
• Macrocells, Small Cells & Hetnets Tutorial

Relays (RN) and Donor eNode Bs (DeNB)

Relays a.k.a. Relay Node (RN) in standards has been a part of the standards for a while but I don't hear about them often. The only time recently when I heard about them were with Airspan's MagicBox small cells deployed in Sprint (see news here). In fact the article speculates:

LTE UE Relay was specified within 3GPP’s Release 10. There are different types of Relay and it would seem Sprint’s will be Type 2, which sees the Relay Node (or MagicBox) retransmit on the same code as provided by its macro “donor” cell.

While I don't have any further details about it, I am not too sure about it. Type 2 relays are complex and require change in the existing eNodeB's. I should clarify here that we are talking about Layer 3 relays in this post. An earlier presentation from Airspan mentioned that they use Type 1a/1b relay architecture. See here.

The presentation below has some nice simple explanation of the Relay nodes and its workings

In case of Type 2 relays, there is a much more architecture change involved. This architecture change requires modification of the existing eNB to Donor eNB (DeNB).

Going back to 3GPP TS 36.300: E-UTRA and E-UTRAN Overall description; Stage 2 document:

The DeNB hosts the following functions in addition to the eNB functions:
- S1/X2 proxy functionality for supporting RNs;
- S11 termination and S-GW/P-GW functionality for supporting RNs.

Further on, in section 4.7

E-UTRAN supports relaying by having a Relay Node (RN) wirelessly connect to an eNB serving the RN, called Donor eNB (DeNB), via a modified version of the E-UTRA radio interface, the modified version being called the Un interface.

The RN supports the eNB functionality meaning it terminates the radio protocols of the E-UTRA radio interface, and the S1 and X2 interfaces. From a specification point of view, functionality defined for eNBs, e.g. RNL and TNL, also applies to RNs unless explicitly specified. RNs do not support NNSF.

In addition to the eNB functionality, the RN also supports a subset of the UE functionality, e.g. physical layer, layer-2, RRC, and NAS functionality, in order to wirelessly connect to the DeNB.

The RN terminates the S1, X2 and Un interfaces. The DeNB provides S1 and X2 proxy functionality between the RN and other network nodes (other eNBs, MMEs and S GWs). The S1 and X2 proxy functionality includes passing UE-dedicated S1 and X2 signalling messages as well as GTP data packets between the S1 and X2 interfaces associated with the RN and the S1 and X2 interfaces associated with other network nodes. Due to the proxy functionality, the DeNB appears as an MME (for S1-MME), an eNB (for X2) and an S-GW (for S1-U) to the RN. 

In phase II of RN operation, the DeNB also embeds and provides the S-GW/P-GW-like functions needed for the RN operation. This includes creating a session for the RN and managing EPS bearers for the RN, as well as terminating the S11 interface towards the MME serving the RN.

The RN and DeNB also perform mapping of signalling and data packets onto EPS bearers that are setup for the RN. The mapping is based on existing QoS mechanisms defined for the UE and the P-GW.

In phase II of RN operation, the P-GW functions in the DeNB allocate an IP address for the RN for the O&M which may be different than the S1 IP address of the DeNB.

Based on the complexity and additional changes required for Type 2 relays, I am not surprised that they are not very popular. If you think otherwise, do let me know.

Thanks to Dr. Kit Kilgour for providing insights into this topic.

Multi-vendor LTE Small Cells SON

Before we proceed further, in case the reader is not aware of Self-Organizing Networks (SON), please refer to my old tutorial here.

BT has recently published a white paper on multi-vendor LTE SON based on tests using LTE small cells provided by Node-H and Qucell. From the news posted on Node-H website:

The white paper focuses on the important issue of interference management between small cells. The paper is the result of a joint effort by British Telecom's Research and Innovation group and the technical teams of Qucell and Node-H. It addresses some of the major challenges of LTE HetNets and expands on the work of the 2016 ETSI Plugfest, which was run under the auspices of the Small Cell Forum. The authors’ conclusion is that interoperability between different vendors' SON implementations is achievable and so operators can look forward to robust, seamless and tailored solutions from multiple vendors.

The white paper shows that it is possible to operate mobile networks in which the individual LTE cells execute different ICIC algorithms. These findings challenge preconceptions about SON that are common in the mobile industry and make the case towards larger multi-vendor deployments of LTE small cells and call for bolder efforts in multi-vendor SON testing.

The ICIC algorithms used during these tests have been developed independently and without exchange of technical details between two separate HeNB vendors. Despite this, it has been shown that both algorithms can gracefully co-exist in the same LTE network. ICIC standardization efforts within 3GPP, along with the Small Cell Forum's Plugfest activities, have been key to this success.

The whitepaper embedded as follows and is available to download from here:

Related posts:

• Interoperability and Plugfests for Multi-vendor HetNet's
• X2: The necessity for Interoperability and Interference management in HetNets

Carrier Aggregation (CA) and Dual Carrier (DC) enhancements in Release-13

Recently I posted a summary whitepaper of 3GPP Release-13 by 5G Americas. This article from NTT Docomo technical journal complements that nicely and provides in depth analysis of selected features.

The article (embedded below) focuses on Carrier Aggregation (CA),Dual Carrier (DC) enhancements, LAA and LWA. In this post, I am going to restrict the discussion to CA and DC.

The following is from the magazine article:

Carrier Aggregation (CA):

Up to Release 12 CA, a maximum of 5 LTE carriers called “Component Carriers” (CCs) could be configured for a User Equipment (UE). This enables a maximum 100 MHz bandwidth for data communications, which achieves a theoretical peak data rates of approximately 4 Gbps, assuming eight Multiple Input Multiple Output (MIMO) layers and 256 Quadrature Amplitude Modulation (QAM) for downlink, and 1.5 Gbps assuming four MIMO layers and 64QAM for uplink.

In Release 13, the maximum number number of CCs that can be configured for a UE simultaneously was increased to 32 to archive higher data transmission rates with wider bandwidths. This enables a maximum 640-MHz bandwidth for data transmission, achieving peak data rates of approximately 25 Gbps for downlink with 8 MIMO layers and 256QAM, and 9.6 Gbps for uplink with 4 MIMO layers and 64QAM.
...
Release 13 introduced the new function to enable PUCCH configuration for a Secondary Cell (SCell) in addition to the PCell in uplink CA. When CA is performed with this function, CCs are grouped together either with the PCell or SCell with PUCCH (PUCCH-SCell). UE sends UCI for CCs within each group by using the PCell or PUCCHSCell. With this new function, uplink radio resource shortages can be resolved by offloading UCI from macro cell to the small cells while keeping the macro cell as the PCell.

Dual Carrier (DC):

Release 12 designed DC to achieve user throughput comparable with that of CA by aggregating multiple CCs across two eNBs. In release 13, DC was further enhanced with higher uplink throughput and more flexible deployment.

In DC, separate eNBs allocate uplink resources independently for a UE. Hence, Release 13 addresses how to allocate adequate uplink resources on multiple CCs for UE. Typically, eNB calculates the required uplink resources based on the uplink buffer amount reported from UE. In DC, since both eNBs calculate the amount of uplink resources based on the report and allocate them to the UE independently, excess uplink resource allocation over actual amount of remaining data will occur. In particular, with small data packets, if resources are allocated by both eNBs, the UE may send all data to only one of them, and send padding (meaningless bit strings) to the other eNB, which wastes radio resources.

To prevent the excess uplink resource allocation for the small data packets described above, new uplink transmission control methods were introduced. In Release 13 DC, UE buffer status reporting and uplink data transmission are controlled based on the amount of uplink data buffered in the UE.

If the amount of the buffered data is smaller than the threshold configured by the eNB, the UE performs buffer status reporting and uplink data transmission only to one of the eNBs, just like DC in Release 12. In contrast, if the amount of the buffered data is larger than the threshold, the UE transmits to both eNBs. This buffer size-based mechanism solves the uplink resource over-allocation problem since only one eNB is aware of the buffered data and allocates resources when the amount of the buffered data is small.


The paper is embedded as follows:

Related posts:

• Inside 3GPP Release-13 - Whitepaper by 5G Americas
• Dedicated Core Networks (DCN) for different traffic types
• New whitepaper on Narrowband Internet of Things
• LTE-Advanced Pro (a.k.a. 4.5G)

Drone cells are becoming a reality

Back in early 2015, the then EE CEO Olaf Swantee said, "We will begin exploring 'Air Masts', essentially aerial small cells positioned in the sky above a hard-to-reach area, using either tethered balloons or unmanned craft, bridging the UK's transmission gap."

The vision has not changed a lot. I recently blogged about 'EE's vision of Ultra-Reliable Emergency Network'. If you look at the slide above you will notice temporary solutions include Air masts, UAV's and Network in a box (NIB).

Nokia recently did a trial with EE where they used a drone to carry a tiny base station to remote areas around Inverness. Weighing in at only 2 kg, the Nokia Flexi Zone Pico cell has all the punch of LTE in a very compact package, allowing 4G services to be provided wherever a drone can reach. High quality LTE voice calls between responders, video streaming and up to 150 Mbps data throughput were all achieved, with no need for a connection to an external core network.

While it doesn't exactly say the area that was covered, I would expect it to be able to do at least 1 km diameter to be effective in an emergency scenario.

According to a recent International Business Times article, US operator AT&T is trying something similar to deal with the struggle to provide enough wireless data are large venue events to please customers. The mobile operator says that drones known as "Flying Cell on Wings (COWs)" could make all the difference. The idea would be that the drone would be tethered to the ground so they would hover in one place, sort of like a portable hovering small cell. 

Finally, Ericsson and China Mobile conduct world’s first 5G drone prototype field trial. In their recent press release it says:

In the trial, held in Wuxi in China’s Jiangsu province, a drone was flown using operator’s cellular network with 5G-enabled technologies and with handovers across multiple sites. In order to demonstrate the concept’s validity in a real-world setting, the handovers were performed between sites that were simultaneously in use by commercial mobile phone users.

The potential use cases for this technology include mission-critical applications such as support for emergency services. However, end-to-end low latency needs to be guaranteed by the operator’s network to ensure the safety and reliability of such services.

I am sure we will be hearing more on this topic soon.

10 million small cells and growing?

There were some good news that was announced in MWC 2015. Here are some interesting points from Total Telecom:

• Operators around the globe have purchased more than 10 million small cells
• In excess of 75 operators worldwide are using small cells in their networks
• The majority of these to date have been deployed in residential scenarios, but we have also seen a significant step upward in the enterprise and urban sectors.
• 17,000 small cells have been deployed in rural or remote applications

While this all sounds good, Small Cells are facing many challenges. The biggest among them being WiFi. With the introduction of VoWiFi, many operators are starting to play a waiting game rather than deploy more small cells.

I blogged back in 2013 that AT&T planned to deploy 40,000 small cells by 2015 but it looks like they have now abandoned their goal. The reason being cited is that they acquired another small operator (Leap Wireless) which gave them additional macro sites, hence removing the need for small cells.

As per a report by the analyst firm ThinkSmallCell, TalkTalk, a UK based "thick" MVNO is trying to deploy an "Inside-out" Femtocell network. They have also been experimenting with 3MHz bandwidth in LTE and surprisingly, it works fine on most devices.


Another option could be to have LTE-LAA/LTE-U along with this and they could provide good speeds not only to the people indoor but also outdoor.

In any case, we will have to wait and see if operators continue rolling out small cells and if they do why, how, where and in which situations.

Tight, Tighter and Very Tight Integration between LTE and WiFi Networks

For those who are unfamiliar about the trusted and non-trusted access, I strongly recommend reading our whitepaper on Cellular and WiFi Integration here.

The standard and the most popular Integration approach between LTE and Wi-Fi is via the Trusted architecture as shown above.

There is a proposal for RAN level Integration which would result in Even Tighter Integration of WiFi

Now some researchers are proposing a Very Tight coupling between LTE and Wi-Fi which would mean that regardless of the access, the UE can be sent data from the same data stream over WiFi and LTE. Though this is radical, these approaches are already being thought about for '5G'. Whether it will happen in a future release of 4G or 4.5G remains to be seen. Here is the complete paper embedded below:

Very Tight Coupling between LTE and Wi-Fi for Advanced Offloading Procedures from Zahid Ghadialy

3G / 4G Small Cells Mobility Scenarios - 3GPP Technical Report

3GPP has an excellent Technical Report (TR) 37.803 that covers different mobility scenarios and enhancements for 3G HNB and 4G HeNB. Its an interesting read if you are involved in this activity. Embedded below for reference.

Mobility enhancements for Home Node B (HNB) and Home enhanced Node B (HeNB) 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. 

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

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.

Small Cells and X2 Interface

In the Release-8/9 of 3GPP, X2 interface between Small Cells and between Small Cells and Macro cells was not available. In Release-10 and 11, this was made available as shown in the picture above.

X2 is not only useful for lossless handovers in LTE/LTE-A but is also very useful for Interference management using eICIC (enhanced Inter Cell Interference Management) feature introduced in Rel-10.

More details on this enhancement is available in 3GPP TS 36.300 here.

US Market for LTE Metrocells to Grow at a 240% CAGR Over Next 5 Years

Under iGR's classification, there are three types of metrocells: those that operate on 3G only, 4G only and those that can operate on both. iGR believes that ultimately the bigger potential market will be for 4G metrocells, albeit by a small margin. 

iGR expects that the total addressable market (TAM) for 4G LTE metrocells in the U.S. will grow at a compounded annual growth rate of nearly 240 percent between 2012 and 2016. 

The TAM for 3G metrocells will initially grow strongly (CAGR over 99 percent between 2012 and 2014) before the opportunity declines in favor of 4G LTE deployments. 

Overall, the combined TAM for both 3G and 4G metrocells grows at a strong CAGR of 50 percent between 2012 and 2016. 

"By 2016, iGR expects the average consumer's consumption of mobile data in the U.S. to increase by ten times over the level in 2011," said Iain Gillott, president and founder of iGR. "The mobile networks must adapt to this vastly increased demand and we see the metrocell, both 3G and 4G versions, as an important part of the solution. Our new study demonstrates the potential for metrocells in the U.S. and shows that the demand in the next five years will far outstrip the number of macro cell sites currently installed."

Complete article here: US Market for LTE Metrocells to Grow at a 240% CAGR Over Next 5 Years:

'via Blog this'

10 Metrocell (3G and LTE) trials in the CALA region

Alcatel-Lucent has long claimed that femtocells and metrocells can boost wireless networks, but this time, it seems that carriers are also betting on the technology. According to Osvaldo di Campli, Alcatel-Lucent’s president of the Caribbean and Latin American (CALA) region, three femtocell contracts have been signed in Brazil, Mexico and Venezuela. Di Campli said that there are ten metrocell trials across CALA, using both metrocell equipment for 3G and LTE, in Brazil, Colombia, Peru, Mexico and Uruguay.
...

However, in Brazil both femtocell and metrocell adoption face challenges. Although the government is studying regulation changes, currently carriers have to pay equal taxes when deploying macrocells, metrocells or femtocells, which can hinder investment.

Complete article here.