Showing posts with label Backhaul. Show all posts
Showing posts with label Backhaul. Show all posts

Saturday, 19 May 2012

Backhauling the Telefonica O2 London LTE Trial

Interesting Video and Presentation about backhaul in the London Trial of LTE deployment by O2.


Presentation:
We have an event in October in Cambridge Wireless that will look at the backhaul and deployments a bit more in detail. Details here.

Sunday, 20 November 2011

Do we need Fiber?


Click on the image to view full size


From a presentation by Acreo, available here.

Thursday, 27 October 2011

Femtocell Backhaul Options


Any others?

There is also this interesting presentation from Maravedis on Non-Line-of-Sight (NLoS) backhaul, embedded below:

Friday, 30 September 2011

Macrocells or Metrocells?

Just went through Alcatel-Lucent strategic paper on whether to go for more Macrocell sites or rather have Metrocells instead.

A good description of Metrocells is available in the document:

Metro cells, the latest evolution in small cells, are based on the same low cost femtocell technology that has been successfully used in home and enterprise cells, but with enhanced capacity and coverage. With higher processing and transmit power, the first generation of metro cells is engineered to serve from 16 to 32 users and provide a coverage range from less than 100 meters in dense urban locations to several hundred meters in rural environments. However, unlike home and enterprise cells, metro cells are owned and managed by a MSP and typically used in public or open access areas to augment the capacity or coverage of a larger macro network.

Available in both indoor and outdoor versions, metro cells are plug-and-play devices that use Self-Organizing Network (SON) technology to automate network configuration and optimization, significantly reducing network planning, deployment and maintenance costs. While indoor versions use an existing broadband connection to backhaul traffic to a core network, outdoor versions may be opportunistically deployed to take advantage of existing wireline or wireless sites and backhaul infrastructure, such as Fiber-to-the-Node (FTTN), Fiber-to-the-Home (FTTH), Very-high-speed Digital Subscriber Line (VDSL) street cabinets, and DSL backbone.

Since metro cells use licensed spectrum and are part of the MSP’s larger mobility network, they provide the same trusted security and quality of service (QoS) as the macro network. With seamless handovers, users can roam from metro cells to the macro network and vice versa. Metro cells also deliver the same services as the macro network (for example, voice, Short Message Service (SMS), and multimedia services), and support application programming interfaces (APIs), that may be used for developing new, innovative services. In short, metro cells promise to be the ideal small cells for network offloading.

For more details on the whitepaper see: http://www.slideshare.net/zahidtg/metro-cells-whitepaper



Friday, 26 August 2011

Two interesting NGMN papers on Backhaul

There are some interesting blog posts on Broadband Traffic Managemenet on Backhaul. Here are few excerpts:

Traditional network management practice says that network element usage level should not exceed 70% of its capacity. If it does - it is time to do something - buy more or manage it better. So, according to a recent Credit Suisse report - it is time to do something for wireless networks, globally. For North America, where current utilization at peak time reaches 80% it is even urgent.

Phil Goldstein (pictured) reports to FierceWireless that - "Wireless networks in the United States are operating at 80 percent of total capacity, the highest of any region in the world, according to a report prepared by investment bank Credit Suisse. The firm argued that wireless carriers likely will need to increase their spending on infrastructure to meet users' growing demands for mobile data .. globally, average peak network utilization rates are at 65 percent, and that peak network utilization levels will reach 70 percent within the next year. .. 23 percent of base stations globally have capacity constraints, or utilization rates of more than 80 to 85 percent in busy hours, up from 20 percent last year .. In the United States, the percentage of base stations with capacity constraints is 38 percent, up from 26 percent in 2010"

And

The Yankee Group provides the following forecast for mobile backhaul:
Average macrocell backhaul requirements were 10 Mbps in 2008 (seven T1s, five E1s). In less than three years, they have more than tripled to 35 Mbps in 2011, and by 2015, Yankee Group predicts they will demand 100 Mbps.
There were 2.4 million macro cell site backhaul connections worldwide in 2010, growing to 3.3 million by [2015?]
Yankee's new research conclude:

"The market for wholesale backhaul services in North America will grow from $2.45 billion in 2010 to $3.9 billion in 2015, with the majority of this growth coming from Ethernet backhaul. Successful backhaul service providers will be those that can demonstrate price/performance and reliability, have software tools in place and can meet the specific needs of the mobile market.

And recently:

A Dell'Oro Group report forecasts that "Mobile Backhaul market revenues are expected to approach $9B by 2015. This updated report tracks two key market segments: Transport, which includes microwave and optical equipment, and Routers and Switches, which includes cell site devices, carrier Ethernet switches, and service provider edge routers .. routers and switches expected to constitute 30% of mobile backhaul market "

Shin Umeda, Vice President of Routers research at Dell’Oro Group said: “Our research has found that operators around the world are concerned with the rate of mobile traffic growth and are transitioning to Internet Protocol (IP) technologies to build a more efficient and scalable backhaul network. Our latest report forecasts the demand for IP-based routers and switches will continue to grow through 2015, almost doubling the market size of the Router and Switches segment in the five-year forecast period”

I have some basic posts on why Backhaul is important, here and here.

NGMN has timely released couple of whitepapers on the Backhaul.

The first one, 'Guidelines for LTE Backhaul Traffic Estimation' document describes how a model is developed to predict traffic levels in transport networks used to backhaul LTE eNodeBs. Backhaul traffic is made up of a number of different components of which user plane data is the largest, comprising around 80-90% of overall traffic, slightly less when IPsec encryption is added. These results reveal that the cell throughput characteristics for data carrying networks are quite different to those of voice carrying networks.

The purpose of second one, 'NGMN Whitepaper LTE Backhauling Deployment Scenarios' is to support operators in their migration from current architectures to new, packet-based backhaul networks. With the introduction of LTE operators need to look at how the backhauling network, the network domain that connects evolved NodeBs (eNBs) to MME and S/P-GW, is capable of adapting to the new requirements, namely the adoption of a packet infrastructure, without disrupting the existing services. This paper introduces some reference architectures, moving from a pure layer 2 topology to a full layer 3 one, discussing some elements to be considered in the design process of a network.

They are both long but interesting read if you like to learn more about Backhaul and the best way in future proofing the network deployments.

Saturday, 30 July 2011

Tuesday, 14 December 2010

What are Heterogeneous Networks (HetNets)?

HetNets are hot. I hear about them in various contexts. Its difficult to find exactly what they are and how they will work though. There is a HetNets special issue in IEEE Communications Magazine coming out next year but that's far away.

I found an interesting summary on HetNets in Motorola Ezine that is reproduced below:


“The bigger the cell site, the less capacity per person you have,” said Peter Jarich, research director with market intelligence firm Current Analysis. “If you shrink coverage to a couple of blocks, you are having that capacity shared with a fewer number of people, resulting in higher capacity and faster data speeds.”

This is a topic the international standards body, the Third Generation Partnership Project (3GPP), has been focusing on to make small cells part of the overall cellular network architecture.

“What we’re seeing is a natural progression of how the industry is going to be addressing some of these capacity concerns,” said Joe Pedziwiatr, network systems architect with Motorola. “There is a need to address the next step of capacity and coverage by introducing and embracing the concepts of small cells and even looking at further advances such as better use of the spectrum itself.”

As such, discussion regarding this small-cell concept has emerged into what is called heterogeneous networks, or Het-Net, for short. The idea is to have a macro wireless network cooperating with intelligent pico cells deployed by operators to work together within the macro network and significantly improve coverage and augment overall network capacity. Small cells can also be leveraged to improve coverage and deliver capacity inside buildings. Indoor coverage has long been the bane of mobile operators. Some mobile operators are already leveraging this concept, augmenting their cellular service offering with WiFi access to their subscriber base in order to address the in-building coverage and capacity challenges facing today’s cellular solutions.

Pedziwiatr said this Het-Net structure goes far beyond what is envisioned for femtocells or standard pico cells for that matter. Introducing a pico cell into the macro network will address but just one aspect of network congestion, namely air interface congestion. The backhaul transport network may become the next bottleneck. Finally, if all this traffic hits the core network, the congestion will just have shifted from the edge to the core.

“This requires a system focus across all aspects of planning and engineering,” Pedziwiatr said. “We’re trying to say it goes beyond that of a femto. If someone shows up at an operator and presents a pico cell, that is just one percent of what would be needed to provide true capacity relief for the macro network.”

Femtocells, otherwise known as miniature take-home base stations, are obtained by end users and plugged into a home or office broadband connection to boost network signals inside buildings. A handful of 3G operators worldwide are selling femtocells as a network coverage play. For the LTE market, the Femtocell Forum is working to convince operators of the value of a femtocell when it comes to better signal penetration inside buildings and delivering high-bandwidth services without loading the mobile network. This is possible, because the backhaul traffic runs over the fixed line connection. However, this femtocell proposition largely relies on end user uptake of them—not necessarily where operators need them, unless they install femtocells themselves or give end users incentives to acquire them.

As with any new concept, there are challenges to overcome before Het-Nets can become reality. Het-Nets must come to market with a total cost of ownership that is competitive for an operator to realize the benefit of providing better capacity, higher data speeds, and most of all, a better end-user experience said Chevli.

“The level of total cost of ownership has to be reduced. That is where the challenge is for vendors to ensure that any new solution revalidates every existing tenet of cellular topology and evolve it to the new paradigm being proposed,” Chevli said. “You can’t increase the number of end nodes by 25X and expect to operate or manage this new network with legacy O&M paradigms and a legacy backhaul approach.”

One of the issues is dealing with interference and Het-Net network traffic policies. “How do you manage all of these small cell networks within the macrocell network?” asked Jarich. “Right now if you have a bunch of femtocells inside a house, there is this concept that the walls stop the macrocell signals from getting in and out. You get a separation between the two. Go outdoors with small cells underlying bigger cells and you get a lot more interference and hand-off issues because devices will switch back and forth based on where the stronger signal is.”

Pedziwiatr said for a Het-Net to work, it would require a change in node management, whereby an operator isn’t burdened with managing big clusters of small cells on an individual basis. “We see elements of SON (self organizing networks), self discovery and auto optimization that will have to be key ingredients in these networks. Otherwise operators can’t manage them and the business case will be a lot less attractive,” he said.

Fortunately, the industry has already been working with and implementing concepts of SON in LTE network solutions. In the femtocell arena also, vendors have been incorporating some elements and concepts of SON so that installing them is a plug-and-play action that automatically configures the device and avoids interference. But even then, Het-Nets will require further SON enhancement to deal with new use cases, such as overlay (macro deployment) to underlay (pico deployments) mobility optimization.

When it comes to LTE, SON features are built into the standard, and are designed to offer the dual benefit of reducing operating costs while optimizing performance. SONs will do this by automating many of the manual processes used when deploying a network to reduce costs and help operators commercialize their new services faster. SON will also automate many routine, repetitive tasks involved in day-to-day network operations and management such as neighbor list discovery and management.

Other key sticking points are deployment and backhaul costs. If operators are to deploy many small cells in a given area, deploying them and backhauling their traffic should not become monumental tasks.

Chevli and Pedziwiatr envision Het-Nets being deployed initially in hot zone areas – where data traffic is the highest – using street-level plug-and-play nodes that can be easily installed by people with little technical know-how.

“Today, macro site selection, engineering, propagation analysis, rollout and optimization are long and expensive processes, which must change so that installers keep inventories of these units in their trucks, making rollout simple installations and power-ups,” said Pedziwiatr. “These will be maintained at a minimum with quick optimization.”

The notion of backhauling traffic coming from a large cluster of Het-Net nodes could also stymie Het-Nets altogether. Chevli said that in order to keep costs down, Het-Net backhaul needs to be a mix of cost-effective wireless or wired backhaul technology to aggregate traffic from what likely will be nodes sitting on lamp posts, walls, in-building and other similar structures. The goal then is to find a backhaul point of presence to aggregate the traffic and then put that traffic on an open transport network in the area.

Backhaul cost reductions may also be a matter of finding ways to reduce the amount of backhaul forwarded to the core network, Pedziwiatr said. These types of solutions are already being developed in the 3G world to cope with the massive data traffic that is beginning to crush networks. For traffic such as Internet traffic, which doesn’t need to travel through an operator’s core network, offloading that traffic as close to the source as possible would further drive down the cost of operation through the reduction of backhaul and capacity needs of the core network.

In the end, with operators incorporating smaller cells as an underlay to their macro network layer rather than relying on data offloading techniques such as femtocells and WiFi that largely depend on the actions of subscribers and impacted by the surrounding cell operating in the same unlicensed frequency, Het-Nets in licensed spectrum will soon become the keystone in attacking the ever-present congestion issue that widely plagues big cities and this is only likely to get worse over time.

Image Source: Dr. Daichi Imamura, Panasonic presentation.

Thursday, 12 August 2010

AT&T on their LTE Backhaul Architecture


Backhaul is a topic that may be giving some operators nightmare. Picked up this slightly old article from Light reading via WirelessMoves.

AT&T network architect Yiannis Argyropoulos addressed the Backhaul Strategies and Core Convergence for Mobile Operators event in New York City and had the following to say:

The lines between wireless and wireline networks are blurring, as are the boundaries between access and core networks, driven by the need to carry the flood of wireless data traffic more efficiently. AT&T is aggressively deploying fiber to its mobile cell sites and migrating from Sonet to Ethernet, but more changes will be needed. AT&T started its fiber push in 2008, and it will take at least seven years to complete, said Argyropoulos.

For the short term, today's metro Ethernet architecture will support LTE, but longer term, the network architecture needs to have less operational complexity, noted the AT&T man. The carrier is in the process of testing new approaches, based in part on work being done by 3rd Generation Partnership Project (3GPP) and the Broadband Forum .

AT&T also is looking for coordination of policy control between its wireline and wireless networks, so that the core network services are the same for end-users, regardless of how they connect to the network. It is no longer adequate for quality-of-service to be delivered piecemeal, within different segments of the network, Argyropoulos stated: "There is a lot of work going on right now to harmonize these."

The early 3GPP scheme for QoS on 3G UMTS networks was too complicated to be implemented, but newer LTE QoS plans from the 3GPP, with nine QoS classes and a smaller number of individual class attributes, look more practical.




The growing volume of data traffic is having an impact on other areas of the carrier's operations, too. The widespread use of bandwidth-hungry smartphone devices is creating new traffic patterns that, among other things, eliminate traditional maintenance windows traditionally scheduled in the early hours of weekend mornings, Argyropoulos pointed out.

"Data traffic peaks at the same time as voice, but it has multiple peaks, and it doesn't ever really subside," he said. That, in turn, is putting pressure on wireless network operators and their vendors to do hitless network upgrades and to build more resiliency into their networks.

AT&T is looking to other means of offloading traffic, including routing optimization that will use gateways strategically placed in the network to direct traffic onto the Internet, and not carry it through the metro and core networks first.

"Most of the mobile data traffic is coming from the Internet and going to the Internet."

It will also be important to offload subscriber traffic generated in the home onto a domestic Internet connection, he added.

To get an Idea of the mobile backhaul load, see my earlier post here.

Along with Fiber, Microwave is also an option and you can read more about it in Daily Wireless blog.

Also came across this blod dedicated to mobile backhaul, that is available here.

Tuesday, 16 March 2010

How to avoid network choking in the future?


If you are looking for an answer to this question then you wont find an answer to that here. Probably no one really knows a complete answer to this question right now. A simple answer would be to have a mix of the Macro cells, Micro cells and Femtocells with some way to offload some more traffic via WiFi.

Earlier this month Skype announced that its client would be able to work on most Symbian phones. I have used the Skype client on phones from '3' and they work great. Skype is even available on iPhones and they were downloaded 1 million times in the first couple of days. Now a big chunk of operator profits come from long distance calls and calls when abroad. If we all start using our phones with Skype, its going to bite into the operators profits. That means they will have to recover this profit from us by another way.

Skype on phones will be used in always on mode, meaning that the networks will get loaded and get congested. A simple solution is to have Femtocells at home that can offload the traffic on Internet. These background apps do cause a considerable amount of traffic and recently an Operator blamed the apps for its network woes.

Femtocells have been targeted generally at the residential market with developments going on for Business users as well. Another smaller Picocells and Microcells are also easily and cheaply available nowadays. With the Ad-Hoc deployment of all these smaller cells, Self Organising Networks (SON) may have a big role to play.

What happens where there are multiple networks present in the same place via these smaller cells? Can the back-haul not get congested because of these multiple networks which may be lying Idle most of the time? How would these impact other services that we use on our PC's?

These questions can be easily answered if a single Microcell/Picocell/Femtocell was able to work for Multiple Networks. Practically this may not be possible right now because each network has a different Authentication and Security arrangement.

At least we can start thinking and working on these problems while we still have time. When its too late, we may have to come up with workarounds. These workarounds only cause more headache in the longer term.

Tuesday, 8 September 2009

Improved LTE backhaul via Alcatel-Lucent's 10G GPON


“The PON vendor landscape got interesting in the fourth quarter of 2008, with Alcatel-Lucent, Motorola, and Tellabs each grabbing 10% of worldwide revenue share, behind perennial leader Mitsubishi and the now number-two player, Fiberhome. In the fast-growing GPON segment, front-runner Alcatel-Lucent is being seriously challenged by Motorola, which increased its quarterly GPON revenue share 5 points in 4Q08. Meanwhile, the EPON segment, long dominated by Mitsubishi and Hitachi, is seeing some action as Sumitomo, Fiberhome, and Dasan Networks all moved up.” - Jeff Heynen, Directing Analyst, Broadband and Video, Infonetics Research

I have blogged a bit about GPON and Backhaul before. Click on the links if you havent seen the posts before.

During this year's Broadband World Forum Europe, Alcatel-Lucent not only shows that it masters next-generation wireline and wireless access. The company also highlights that Long Term Evolution (LTE) and next-generation passive optical networking (PON) technologies converge seamlessly for a smooth delivery of the most demanding, high-speed broadband services.

The live demonstration in Alcatel-Lucent's Paris demo center shows LTE's capability to deal with multiple concurrent video streams and fast channel change - and is complemented by a high-capacity 10G GPON backhaul solution for future-safe backhaul via fiber.

Alcatel-Lucent is at the forefront of developing cutting-edge technologies long before they are standardized. Even though the 10G GPON standards are still being ratified, Alcatel-Lucent shows it is ready - when needed - to meet the request for higher capacities in its customers' access networks.

Alcatel-Lucent is engaged in over 95 FTTH projects around the world, over 80 of which are with GPON (as-of Q2, 2009). In Gartner's latest FTTH Magic Quadrant assessment, Alcatel-Lucent was positioned in the leaders quadrant for the fiber-to-the-home space.

Alcatel-Lucent is also opening up details of its optical management and control interfaces (OMCIs) in a bid to help create a true multi-vendor gigabit passive optical networking (GPON) infrastructure.

Announced at this year's Broadband World Forum Europe in Paris, the first version of the OMCI Interoperability Implementer's Guide is aimed at helping other optical network terminal vendors integrate their hardware with Alcatel-Lucent's.

Sunday, 1 February 2009

Mobile Backhaul Networks and their Load

These are self explanatory slides on Mobile Network Backhaul presented by Professor Steve Ferguson, Head of Market Strategy, Product Area Broadband Networks, Ericsson in the LTE World Summit last year.



Tuesday, 9 December 2008

LTE Advanced: NSN Proves relaying technology



Nokia Siemens Networks has broken new ground with another technological first: mobile broadband communications beyond LTE. Company researchers have successfully demonstrated Relaying technology proposed for LTE-Advanced, enabling an exceptional end-user experience delivered consistently across the network.

Completed in Nokia Siemens Networks research facilities in Germany, the demonstration illustrated how advances to Relaying technology can further improve the quality and coverage consistency of a network at the cell edge - where users are furthest from the mobile broadband base station.

Relaying technology, which can also be integrated in normal base station platforms, is cost efficient and easy to deploy as it does not require additional backhaul. The demonstration of LTE Advanced means operators can plan their LTE network investments knowing that the already best-in-class LTE radio performance, including cell edge data rates, can be further improved and that the technological development path for the next stage of LTE is secure and future-proof.

These performance enhancements have been achieved by combining an LTE system supporting a 2x2 MIMO (Multiple Input Multiple Output) antenna system, and a Relay station. The Relaying operates in-band, which means that the relay stations inserted in the network do not need an external data backhaul. They are connected to the nearest base stations by using radio resources within the operating frequency band of the base station itself. Towards the terminal they are base stations and offer the full functionality of LTE. LTE-Advanced is currently being studied by 3GPP for Release 10 and will be submitted towards ITU-R as the 3GPP Radio Interface Technology proposal.

The improved cell coverage and system fairness - meaning offering higher user data rates for and fair treatment of users distant from the base station - will allow operators to utilise existing LTE network infrastructure and still meet growing bandwidth demands.

The demonstration has been realised by using an intelligent demo relay node embedded in a test network forming a FDD in-band self-backhauling solution for coverage enhancements. With this demonstration the performance at the cell edge could be increased up to 50% of the peak throughput.


More info on LTE-A coming soon.