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Wireless

Mobility Lab Webinar Recap: Over-the-Top (OTT) Aggregation

Omkar Dharmadhikari
Wireless Architect

Feb 14, 2019

This week, we hosted our second installment of the Mobility Lab Webinar series on “Over-the-Top (OTT) Aggregation.” If you were unable to attend the webinar, you can read about it in this blog or scroll down to see the recorded webinar and Q&A below.

Background

Wireless operators have always been driven to meet increasing user demand by achieving higher data rates and improving quality of service. To fulfill these needs, wireless operators have used various types of carrier aggregation, including several commonly used industry-standard solutions:

  • Traditional multi-carrier aggregation
  • Aggregating carriers in either licensed or unlicensed spectrum, using a single technology like LTE
  • Aggregating carriers by using both LTE in licensed spectrum and Wi-Fi in unlicensed spectrum

Each aggregation solution offers benefits such as higher date rates, improved QoS, more efficient spectrum utilization and enhanced user experience. But these benefits need to be weighed against certain tradeoffs in terms of capital investments, deployment complexities, spectrum and network infrastructure ownership. This may result in barriers for Multiple Service Operators (MSOs) with no cellular infrastructure.

Our Webinar: Over-the-Top (OTT) Aggregation

OTT aggregation is an alternate solution to industry-standard aggregation solutions. OTT aggregation solutions leverage existing cellular and Wi-Fi infrastructures without requiring any significant changes on the network and end-user devices. Thus, OTT aggregation solutions offer an economical approach for an MSO to provide high data rates and improved user experience.

The webinar provides the following:

  • An understanding of why aggregation is important
  • An overview of traditional aggregation solutions
  • A detailed description of OTT aggregation solutions compared with industry-standard aggregation solutions
  • An overview of the testing conducted by CableLabs to validate the benefits of aggregation solution on end-user throughput and quality of experience (QoE)

To learn more about this topic, please use the links below:

Stay tuned for information about upcoming webinars. If you have any questions, please feel free to reach out to Wireless Architect Omkar Dharmadhikari.


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Wireless

DOCSIS® Network vs. Fiber BackHaul for Outdoor Small Cells: How Larger Footprint of DOCSIS Networks Lowers TCO in the Outdoor Use Case

Shahed Mazumder
Principal Strategist, Wireless Technologies

Joey Padden
Distinguished Technologist, Wireless Technologies

Jennifer Andreoli-Fang
Distinguished Technologist, Wireless Technologies

Jan 31, 2019

In our recent blog post, we talked about how, from a total cost of ownership (TCO) perspective, DOCSIS networks triumph as either backhaul or fronthaul over traditional fiber backhaul for the indoor use case. In this blog, we bring that TCO analysis to a more intuitive, outdoor use case: a head-to-head comparison between TCO of DOCSIS backhaul and fiber backhaul, both of which serve the same set of outdoor small cells.

The basic idea here is: leverage the existing real estate of DOCSIS networks for additional use cases beyond residential/business services. This approach applies to the markets where DOCSIS networks already have a larger footprint than the fiber on the ground. We have seen data points suggesting that there typically is 3~5X more coax cable than fiber in major North American metro markets. This enables a large subset of small cells to be deployed on cable strands or at a short distance from the cable strands, using short drops.

Through primary research, one of our members with dual operations (cable + wireless) confirmed that from a small cell radio planning perspective, they exhaust all cable strand mounting options first, before looking into the gaps for additional sites. This is the key differentiator for DOCSIS technology vs. fiber, where most of the backhaul connections require either new build or premium lease rates.

In this TCO analysis, we showed >50% reduction in TCO for an outdoor use case of backhauling small cells when served by DOCSIS networks compared to a more traditional deployment served by fiber. 

But, Is DOCSIS Network the Right Solution for Small Cell Backhauling?

The short answer is – YES.

There are two major requirements associated with any small cell deployment –

  • Site acquisition/preparation/construction/powering
  • Backhaul with certain capacity/latency/timing synchronization

These two requirements are intertwined since we need to choose a site where backhauling option/s are available and, to the extent possible, cost-effective.

In terms of site (1st requirement) with ready access to backhaul, MSOs have 2 offers on the card:

  • Firstly, co-siting small cells with existing MSO owned/operated WiFi hotspots which are already served by DOCSIS backhaul.
  • Secondly, leveraging existing cable infrastructure, and in particular aerial plant i.e., cable strands, that takes out a lot of steps (and cost) from the small cell deployment process. Using existing infrastructure eliminates/lightens the need for permitting and site acquisition, preparation/construction and also powering. Along with site access (typically covered by existing pole-line attachment agreements) and power, cable strand deployments also come with readily accessible DOCSIS links as backhaul.

Figure 1 below shows a typical strand-mount small cell installation, consisting of a small cell gateway and a 4G/LTE-A small cell as reported in the technical paper prepared for SCTE-ISBE 2018 Fall Technical Forum by Dave Morley from Shaw Communications Inc./Freedom Mobile. The small cell gateway here contains a DOCSIS 3.1 cable modem and power supply.

Typical Strand Mount Small Cell

Figure 1: Typical Strand Mount Small Cell @ Shaw Communications Inc./Freedom Mobile

In terms of backhaul specifications (2nd requirement), Belal Hamzeh and Jennifer Andreoli-Fang from CableLabs® have articulated how DOCSIS technologies, with recent developments, fulfills all three fundamental backhaul needs around capacity, latency, and timing in the technical brief titled DOCSIS Technologies for Mobile Backhaul (CableLabs members only). In that paper, the authors have argued that, depending on the mobile operator’s defined SLA, even DOCSIS 3.0 can support backhaul capacity needs. And, significant downstream capacity improvement can be added with DOCSIS 3.1 and significant upstream capacity improvement can be added with Full Duplex DOCSIS.

Regarding latency, control and user plane latency is expected to improve significantly, achieving ~1-2ms latency with the pipelining/Bandwidth Report (BWR) technique across DOCSIS and mobile technologies. Finally, DOCSIS 3.1 already has the mechanism to natively distribute IEEE-1588 timing over the network. With recent CableLabs work on a DOCSIS synchronization specification, DOCSIS 3.1 will also be able to achieve the stringent phase precision as required in LTE TDD/5G networks.

Therefore, in summary, DOCSIS meets the requirements associated with small cell deployment, triggering the need to compare its TCO with traditional fiber based TCO when either one can provide the backhaul for a set of newly deployed small cells in a target market. 

Deployment Scenarios We Looked At

For TCO analysis, we considered a hypothetical market covering 100 sq.km. with 290K housing units (HU) and ~700K people in it. There will be 640 outdoor small cells deployed in the market with 150Mbps/50Mbps max DL/UL throughput per cell (20MHz 2*2 LTE cell). For simplicity, using 1:1 mapping between radio and backhaul throughput, we considered peak backhaul capacity of 150Mbps/50Mbps per small cell.

However, since the peak data rates are required/achieved only under ideal conditions, the average DL/UL throughput during the busy hour is much lower, typically 20-25% of the peak rates. We considered the average throughput to be 20% of the peak, thus forming a small cell cluster comprised of 5 small cells that results in 128 total small cell clusters in our market. Each of these clusters is served by a single cable modem capable to handle 150Mbps/50Mbps.

We have 2 identical scenarios: Scenario A, with fiber backhaul and Scenario B, with DOCSIS backhaul, both serving the same market with 128 clusters i.e. 640 total small cells.

Scenario A: Outdoor small cell served by fiber backhaul

Scenario A: Outdoor small cell served by fiber backhaul

 

Scenario B

Scenario B: Outdoor small cell served by DOCSIS backhaul

TCO Analysis and Key Takeaways

In this analysis, for both scenarios, we assumed the need for 3 types of backhaul connectivity to bring the small cells online – new build (both scenarios), existing cable strand/MSO WiFi Hotspots (scenario B only), and short drop (~300ft) to site/pole from nearby network (both scenarios).

In our base case, for the 2 scenarios, we applied the following breakdown among types of backhaul connectivity required:

Table 1:  Backhaul Connectivity Type Distribution Assumed for Base Case

Table 1:  Backhaul Connectivity Type Distribution Assumed for Base Case

The distribution of backhaul connectivity type used in our base case is informed based on primary research and market observations. Obviously, there is no one size fits all and this is a key area to assess when an operator analyzes potential TCO savings in a target market. Scenario B’s attractiveness largely depends on the ratio (2/3rd in our base case) of existing cable strand/WiFi hotspots that an MSO can leverage to deploy small cells.

The cost difference between new build and short drop does not come from site acquisition/ preparation/ installation because that need will be identical for both types. However, backhaul lease amount (/month) is different for these two types in our 100% Opex based model for backhaul cost.

Though configurable in our model, our default TCO term is 7 years. Also, we calculated the TCO per user passed and focused on the relative difference among scenarios to de-emphasis the overall cost (in dollars), which will differ by markets, the scale of deployment and supplier dynamics among other things.

Figure 2: Summary of 7-Yr. TCO between 2 Deployment Scenarios of Outdoor Use Case 

Figure 2: Summary of 7-Yr. TCO between 2 Deployment Scenarios of Outdoor Use Case

According to our base case assumptions, we see the following:

  • TCO in DOCSIS BH scenario has the potential to be >50% cheaper than the TCO in fiber BH scenario
  • The major difference in TCO between the two scenarios come from Opex. This is because, all 3 key Opex contributors – site lease, site utility cost, and backhaul lease are significantly higher (3~5X) in scenario A than in scenario B.
  • There also is a major difference in Capex between the two scenarios. This is largely because, site acquisition/preparation in scenario A costs more (2~2.5X) than the same category of Capex in scenario B, due to the advantage DOCSIS holds for leveraging more existing sites.
  • We allocated 20% of DOCSIS network upgrade (from low split to mid split) cost to the DOCSIS scenario. If we take this out (since DOCSIS network upgrades will happen anyway), the Capex associated with plant upgrade cost in scenario B will be gone, making it even more attractive from TCO perspective.
  • As mentioned earlier in Table 1, the TCO analysis outcome is primarily dependent on base case assumptions for the distribution of BH connectivity types. If existing cable strand/WiFi hotspots can handle 80% of small cell sites, then, instead of ~50%, the TCO for scenario B will be reduced by ~60%. On the contrary, if that ratio drops down to 50%, then TCO reduction in scenario B will also come down to ~40%.

In an upcoming strategy brief (CableLabs member operators only), we intend to share more details on our methodology, assumptions and breakdown of observed results (both Capex and Opex) along with a full sensitivity analysis.

Conclusion

As we also mentioned in our previous blog (on indoor use case), it’s self-evident that a DOCSIS network-based deployment would have favorable economics compared to a fiber-based model just by virtue of its larger footprint/incumbency alone. When we throw in additional advantages such as lower power requirement/utility charges, that gap only widens. Our TCO model introduced here quantifies that perceived benefit and numerically shows the cost savings in serving outdoor small cells via DOCSIS. This sort of use case strengthens our view that DOCSIS technology has a huge role to play in 5G deployments.

Subscribe to our blog and stay tuned as we continue to explore how to leverage DOCSIS network for mobile deployments. In our next blog post of this series, we intend to look at the DOCSIS networks’ ability to support advanced features such as CoMP.


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Wireless

Mobility Lab Webinar #2: Over-The-Top (OTT) Aggregation

Omkar Dharmadhikari
Wireless Architect

Jan 23, 2019

Achieving higher data rates and increasing quality of service (QoS) have always been driving forces for wireless operators to meet increasing user demand for higher throughputs.

To address this need, operators have used various flavors of aggregation, including:

  • Traditional multi-channel aggregation
  • Aggregating carriers in either licensed or unlicensed spectrum, using a single technology like LTE
  • Aggregating carriers by using both LTE in licensed spectrum and Wi-Fi in unlicensed spectrum

Each aggregation solution has its own benefits in terms of higher data rates, better QoS, better spectrum utilization and better user experience. Along with these benefits come certain tradeoffs in terms of capital investments, complexities, the need to own spectrum and the need to own certain network components. The necessity to own spectrum and certain network components result in barriers for Multiple Service Operators (MSOs) that are trying to enter the market to provide cellular services.

OTT Aggregation Differentiation

OTT aggregation solutions can be implemented irrespective of what cellular network assets the MSOs own. OTT aggregation solutions, as shown in the figure below, leverage existing cellular and Wi-Fi infrastructures without requiring any significant changes on the network and end devices. Thus, an OTT aggregation solution provides an economical way for MSO to provide high data rates and improved user experience.

OTT Aggregation Solution

The key advantages of OTT aggregation solutions over other aggregation solutions include:

  • Providing high data rates in an economical way with no changes required to the existing LTE and Wi-Fi networks and with no additional device support needed
  • Gapless handovers with IP continuity and aggregation across all heterogeneous networks without access to Mobile Network Operators’ (MNOs’) Evolved Packet Core (EPC)
  • Ability to set customized policies and manage Quality of Service (QoS) without access to MNOs’ EPC
  • Ability to aggregate MSO-owned Wi-Fi network with third-party (private) Citizen’s Band Radio Service (CBRS) networks

More About OTT Aggregation Solutions

CableLabs is hosting another webinar as part of the “Mobility Lab Webinar Series” about “Over-The-Top (OTT) Aggregation Solutions,” scheduled for February 12, 2019.

The webinar will provide:

  • An understanding of why aggregation is important
  • An overview of traditional aggregation solutions
  • A detailed description of OTT aggregation solutions compared with other aggregation technologies
  • An overview of the testing conducted by CableLabs to validate the benefits of aggregation solution on end-user throughput and quality of experience (QoE)
  • A lab demonstration of OTT aggregation using CBRS and Wi-Fi networks

Stay tuned for information on further webinars in the pipeline. In case of any questions/suggestions, please feel free to reach out to Omkar Dharmadhikari, Wireless Architect, CableLabs or Mark Poletti, Director of Wireless, CableLabs. Register for this Webinar by filling out the form below:



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Wireless

TCO of DOCSIS® Network XHaul vs. Fiber BackHaul: How DOCSIS Networks Triumph in the Indoor Use Case

Shahed Mazumder
Principal Strategist, Wireless Technologies

Joey Padden
Distinguished Technologist, Wireless Technologies

Jennifer Andreoli-Fang
Distinguished Technologist, Wireless Technologies

Dec 12, 2018

In our recently published blog post, we demonstrated why indoor femtocells have reemerged as an attractive deployment model. In particular, indoor network densification has huge potential for converged cable/wireless operators who can leverage their existing Hybrid Fiber Coax (HFC) footprint to either backhaul from full-stack femtocells or fronthaul from virtual Radio Access Network (vRAN) remote radio units.

In the second blog in our series, we shift the focus from system level benefits to making the business case. As we walk through our TCO model, we will show a 40% to 50% reduction in Total Cost of Ownership (TCO) for an indoor deployment model served by DOCSIS networks compared to a more traditional outdoor deployment served by fiber. Yeah, that is big, so let’s break down how we got there.

Why DOCSIS Networks?

Before jumping into the TCO discussion, let’s revisit the key motivations for using DOCSIS networks as a tool for mobile deployments:

  • Broad-based availability: In a Technical Paper prepared for SCTE-ISBE 2018 Fall Technical Forum, a major Canadian MSO pointed out that there typically is 3~5X more coax cable than fiber in its major metro markets. In the US too, per FCC’s June 2017 statistics, nation-wide cable Household Passed (HHP) stands at 85% (115M units), whereas fiber HHP stands at 29% (39M units)
  • Gigabit footprint: As of June 2018, over 63% of US homes have access to gigabit service over cable. In other markets cable operators are pushing ahead with gigabit buildout as well
  • Ease of site acquisition: No permitting, no make ready, limited installation effort.
  • Evolving mobile-friendly technology: Ranging from latency optimization to timing/synchronization techniques and vRAN support for non-ideal fronthaul links like DOCSIS networks.

Scenarios We Looked At

For TCO comparison, we looked at the following 3 deployment scenarios:

Scenario 1: Outdoor small cell served by leased fiber backhaul

Scenario 1

This is the traditional solution for deploying small cells. For our TCO model, we treated this as the baseline.

Scenario 2: Indoor femtocell/home eNodeB served by residential/SMB DOCSIS network links as backhaul.

Scenario 2

In this scenario, we modeled the deployment of a full-stack femtocell in residential customer homes and small to medium businesses (SMB) served by the converged operator’s DOCSIS network. A converged operator here refers to a cable operator that deploys both DOCSIS network and mobile networks.

Scenario 3: Indoor vRAN Remote Radio Unit (RRU) served by residential/SMB DOCSIS network links as fronthaul

Scenario 3

Scenario 3 is essentially scenario 2 but using vRAN. In this case, the virtual base band unit (vBBU) could be deployed on general purpose processors (GPP) servers in the distribution hub site with low-cost radio units deployed in DOCSIS gateways at the customer premise, or SMB location.

Apples to Apples

To build the TCO model, we start with a representative suburban/urban area we want to model. In our case, we used a 100 sq. km area with a total of 290k households (HH). At 2.4People/HH (the US average), our modeled area covered roughly 700K people.

Next, we considered that this area is already served by 10 outdoor macrocells, but the operator needs to boost capacity through network densification.

Under Scenario 1, the operator deploys 640 outdoor small cells that cut existing macro cells’ traffic load by half and boost the spectral efficiency (and therefore capacity) across the network. To create an apples-to-apples comparison of system capacity under all three scenarios, we applied the concept of normalized spectral efficiency (SE) and kept that consistent across the three scenarios. For SE normalization, we added up weighted SE for different combinations of Radio Location-User Location (e.g. In-In, Out-Out, Out-In) in each scenario.

In the end, we used the normalized SE to find the appropriate scale for each scenario to achieve the same result at the system level, i.e. how many femtocells/vRAN radios will be required in indoor scenarios (2 & 3) so the system capacity gain is comparable to the traditional deployment in scenario 1.

Work Smarter, Not Harder

Crucially, converged operators know who their heavy cellular data users are and among them, who consistently use the network during non-business hours, i.e., most likely from their residences. As an example, a CableLabs member shared empirical data showing that the top 5% of their users consume between 25%~40% of overall cellular network capacity on a monthly basis.

So as a converged operator, if you want to prevent at least 25% of network traffic from traversing through walls, you can proactively distribute home femtocells or RRUs to only the top 5% of your users (assuming their entire consumption happens indoor).

In our model, we used the following approach to get the scale of indoor deployment for scenarios 2 and 3:

Figure-A: Determining Scale of Deployment for Indoor Use Cases

Figure-A: Determining Scale of Deployment for Indoor Use Cases

Therefore, theoretically, if only 2.5% of subscribers start using indoor cellular resources, we can achieve the same SE improvement in scenarios 2 and 3, as observed under scenario 1’s fiber outdoor deployment.

However, we know assuming 100% of heavy users traffic is consumed at home or indoors is unrealistic. To account for a combination of real-world factors including that indoor doesn’t mean only at your residences, that some of those heavy user locations may not be serviceable by a DOCSIS network, and/or some users may opt out from using a home femtocell/RRU we boosted that percentage of the subscriber base we modeled using femtocell/RRU deployments to 12.5% (or roughly 35K units) to make sure that we can definitely capture at least 12.5% of cellular traffic in scenario 2 and 3.

Our Analysis and Key Takeaways

For the TCO model assumptions, we gathered a wide range of input from a number of CableLabs operators and vendors. In addition, we validated our key assumptions with quite a few Telecom Infra Project (TIP) vRAN fronthaul project group’s members.

Though configurable in our model, our default TCO term is 7 years. Also, we calculated the TCO per user passed and focused on the relative difference among scenarios to de-emphasis the overall cost (in dollars), which will differ by markets, the scale of deployment and supplier dynamics among other things.

Figure-B: Summary of 7-Yr. TCOs across 3 Deployment Scenarios

Figure-B: Summary of 7-Yr. TCOs across 3 Deployment Scenarios

According to our base case assumptions, we see the following:

  • TCO in scenarios 2 and 3 can be around 40%~50% cheaper than the TCO in scenario 1.
  • For scenario 1, Opex stands out as it involves large fees associated with outdoor small cell site lease and fiber backhaul lease.
  • Scenario 2 commands a higher Capex than scenario 3, largely because of higher (~2X) unit price per full-stack home femtocell (vs. home RRU) and the need for security gateway, which is not required in scenario 3.
  • Scenario 3’s Opex is nearly double (vs. scenario 2 Opex), as it requires a significantly higher DOCSIS network capacity for the upstream link. Yet, notably, despite the increased DOCSIS network capacity used by a vRAN deployment, the TCO is still the most favorable.
  • We allocated 20% of DOCSIS network upgrade (from low split to mid split) cost to DOCSIS network-based use cases (scenarios 2 and 3). If we take those out (since DOCSIS network upgrades will happen anyway for residential broadband services) the TCO of these indoor use cases get even better compared to the fiber outdoor case (scenario 1).
  • Other key sensitivities include monthly cost/allocated cost of the XHaul, number of small cell sites within a small cell cluster, radio equipment cost, and estimated number/price of threads required for vBBU HW to serve a cluster in the vRAN scenario.

In an upcoming strategy brief (CableLabs member operators only), we intend to share more details on our methodology, assumptions and breakdown of observed results (both Capex and Opex) along with a sensitivity analysis.

What Do These Results Mean?

To us, it was always a no-brainer that a DOCSIS network-based deployment would have favorable economics compared to a fiber-based model. The TCO model introduced here confirms and quantifies that perceived benefit and points out that for network densification, there is a business case to pursue the indoor femtocell use case where market conditions are favorable.

Subscribe to our blog because our exploration of DOCSIS networks for mobile deployments isn’t over. Coming up next we explore a similar TCO model focused on outdoor deployments served by DOCSIS backhual. Later we will shift back to technology as we look at the DOCSIS networks ability to support advanced features such as CoMP.


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Wireless

Wireless RF Spectrum Scarcity, What About Light Wave?

Lili Hervieu
Lead Architect, Wireless Research & Development at CableLabs

Dec 5, 2018

The scarcity of unlicensed RF spectrum is a never-ending subject in the wireless industry. The 2.4 and 5 GHz bands, once considered profuse, are now overcrowded and regulators such as the FCC are planning to release 1.2 GHz of bandwidth in the 6 GHz band. Over the last decade, this has fueled a growing interest in Light Communication (LC) technologies that offer the potential of THz of unlicensed spectrum including visible light, near-infrared and near-UV. Standard LEDs are now providing illumination while transmitting data at a high rate, and laser diodes (LDs) can reach ~100 Gbps in point to point communications. The recent introduction of products on the market for internet access and wireless backhauling show that the technology is becoming a reality.

What Is Light Communication?

In light communications, the signal is transmitted by an emitting diode (LED/LD) using Intensity Modulation, where the brightness of the light is modulated at a high frequency, imperceptible to the human eye. At the receiver, a photodiode or a camera image sensor converts the received optical power to an electrical signal using Direct Detection. Dimming is possible but often impacts the performance of the system. Rates of Multi-Gbps have been demonstrated with standard phosphor-coated LEDs (1 Gbps) or RGB LEDs (3 Gbps), using advanced modulation technics such as OFDM. Laser Diodes achieves higher data rate over much longer distances but are not always practical in consumer application due to potential health issue and the quality of laser light for illuminations.

LC offers the advantages of a large, unregulated, license-free spectrum, and is already capable in lab environment of reaching 100 Gbps (near field communication). The technology is particularly adapted to environments where RF communications are restricted or pose health concerns. LC is also considered as more “secure” against hackers since the communication is confined in the cone of light within a well-defined coverage zone. Line of Sight (LOS) is required for most use cases.

LC Applications: From Specialized to Mass Markets

With the technology being quite recent, different industries including lighting, transportation, industrial/manufacturing and telecommunication are evaluating its potential.

Specialized markets include location-based services where illuminations can provide a precise location. “Light beacons” are received by smartphone’s camera (supported by recent cell phone models) and an App provides services to enhanced user experience in retail stores or museum places. The aerospace industry is also considering LC to deliver in-flight entertainment.

Outdoor terrestrial link scenarios are attracting much interest fueled by the need of cost-effective wireless backhauls, especially in the context of 5G (small cells). The laser diode transmission usually operates on the near-infrared spectrum due to lower attenuation levels. The technology is part of the Free Space Optic (FSO) communication family that requires a strict line of sight. Available solutions reach 1 Gbps over up to 300 meters with a good reliability, and speeds up to 10 Gbps are on roadmaps. Over longer distances, however, bad weather conditions, especially fog and dust, can significantly affect the throughput. For this reason, the technology is often complemented with mmWave which is mostly affected by rain.

The mass market opportunity, however, resides in the Wireless Local Area Network (WLAN) applications where the technology, referred as Light Fidelity (Li-Fi), can complement or, in some cases, replace Wi-Fi. IEEE 802 has recently added a Light Communication task group (802.11bb) to complement the 802.11 family, recognizing the potential of Li-Fi. The standard specifies a PHY operating in the in 380 nm to 5,000 nm band (visible light, near-infrared, near-UV) targeting data rate from 10 Mbps up to at least 5 Gbps for a single link throughput. The uplink in Li-fi systems is usually based on IR transmission due to power limitation of the mobile devices and potential glare of visible light to the user.

Environments that restrict the use of EMI (Electromagnetic Interference) such as hospital, schools and factories are likely to fuel the industry in the next 5 years. The office/enterprise environment is also well suited for Li-Fi where lighting is ubiquitous and Power Over Ethernet is available and serves as a backhaul.  In residential environments, Li-Fi can locally offload traffic in heavily populated apartments where RF interference is the primary concern. All these applications are addressed by the 802.11bb standard, while ITU G.vlc focuses on the residential environment.

light communications

Light communication is a promising technology that is still in its infancy. The growing interest in this technology is driven by the availability of a huge unlicensed spectrum not susceptible to RF interferences. As CableLabs continues to focus on developing new and innovative wireless technologies, light communications will definitively stay on the radar.

To stay current with what CableLabs is doing in the wireless space, make sure to subscribe to our blog.


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Converged Carriers, Femtocells and Spectral Efficiency: Rethinking the Traditional Outdoor Small Cell Deployment

Joey Padden
Distinguished Technologist, Wireless Technologies

Nov 15, 2018

With the release of any new generation, or “G,” in the cellular world, the goal is always to outperform the previous generation when it comes to spectral efficiency—that is, how many bits you can pack into your slice of airwaves. To telecom nerds, this is expressed as bits per second per hertz (bps/Hz). Going from 3G to 5G, peak spectral efficiency skyrockets from 1.3 bps/Hz with 3G, to 16 bps/Hz with 4G LTE , to 30 bps/Hz with LTE-A, and to a truly eye-watering 145 bps/Hz with 5G (in the lab).

And it makes sense: Spectrum is an expensive and limited resource. Operators pay billions for every MHz they can acquire.

Not What It Seems

Unfortunately, the reality of spectral efficiency in deployed mobile networks is far less stratospheric. A 2017 study pegged spectral efficiencies for a live LTE network at roughly 1 bps/Hz on average with a peak of about 5.5 bps/Hz. So where did all that spectral efficiency go?

The short answer is that it ran smack into a wall. Literally! In 2016, ABI Research Director Nick Marshall said that “more than 80 percent of all traffic [is] originating or terminating indoors,” and we serve the vast majority of that traffic with outdoor cells.

The Inertia of Tradition

In the push toward 5G, we hear a lot about network densification. So far, given the amount of effort going into changing the siting rules, it sounds like the plan is to deploy more outdoor cells to help increase spectral efficiency in 5G networks. In a recent RCR Wireless News article, the headline read “US outdoor small cell antenna shipments to grow by 75% in 2018: Study” citing a study by EJL Wireless Research.

Putting aside the immense issues facing the economics of that approach (more on that in the next blog post covering our TCO analysis), it still relies on an architecture of deploying outdoor cells to handle a largely indoor traffic load. It still puts literal barriers in the way of increased spectral efficiency.

Airtime Perspective

Let’s quantify this issue a bit to make sure we have a shared perspective on the system capacity impact of using outdoor cells to handle indoor traffic because it’s a big deal.

Small cell DOCSIS

Sending a typical video packet from an outdoor cell to an outdoor user takes 33 resource blocks, whereas sending that same frame to a deep indoor user can take 209 resource blocks (1500B IP packet, I_TBS 3 vs I_TBS 19, TM2 with 2TRx)! On average, it takes seven times more airtime resources to serve an indoor user than an outdoor user.

Given the inefficiency, why are we still trying to cross the walls?

User Behavior

It’s probably not news to anyone that indoor penetration is costly. A common industry view says that when a user is indoors, his or her data should be served by Wi-Fi to offload the burden on the cellular network. Industry reports are produced every year showing that large amounts of traffic from mobile devices are offloaded to Wi-Fi networks (e.g., ~80 percent in 2017).

However, as the industry moves toward unlimited data plans, and as mobile speeds increase, the incentives for seeking out Wi-Fi for offload are diminishing. A recent CableLabs Strategy Brief (CableLabs membership login required) provides empirical data showing that Wi-Fi data offload is declining as adoption of unlimited data plans increases. The trend, across all age groups, shows increased cellular data usage. So as demand for cellular data is going up, an increasing portion is going to be crossing the walls.

There are a number of long-held complaints about the Wi-Fi user experience. I won’t enumerate them here, but I’ll point out that as the incentives to offload data to Wi-Fi are weakened, even the slightest hiccup in the Wi-Fi user experience will drive a user away from that offload opportunity at the expense of your cellular system capacity.

Introducing Low-Cost Femtocells

There’s a growing breed of operator that has both cellular operations and traditional cable hybrid fiber coax (HFC) infrastructure—a big wired network and a big wireless network (Note: here I am talking about full MNOs with HFC/DOCSIS networks, not MVNOs. MVNOs with HFC/DOCSIS networks will have different goals in what optimizing looks like). For these operators, the carrots of convergence dangle in all directions.

Over the past couple of years, CableLabs has ramped up efforts to solve the technology issues that have traditionally hindered convergence. Latency concerns for backhaul or vRAN fronthaul can be resolved by the innovative Bandwidth Report project. CableLabs leadership in the TIP vRAN Fronthaul project is making latency-tolerant fronthaul protocols a reality. Timing and synchronization challenges presented by indoor deployments are months away from commercialization, thanks to CableLabs’ new synchronization spec.

The summation of these projects (and more on the way) provides a suite of tools that converged operators can leverage to deploy mobile services over their HFC/DOCSIS network.

Enter the femtocell deployment model. Femtocells aren’t new, but with the new technologies developed by CableLabs, for the first time, they can be done right. Gone are the days of failed GPS lock, poor handover performance, and interference issues (topics of our 3rd blog in this series). From a spectral and economic viewpoint, femtocells over DOCSIS are poised to be the most efficient deployment model for 4G evolution and 5G cellular densification.

Wi-Fi Precedence

Take Wi-Fi as a guide to how femtocells can improve spectral efficiency. Modern Wi-Fi routers—even cheap home routers—regularly provide devices with physical link rates approaching 10 bps/Hz. That is a huge gain over the sub-1 bps/Hz achieved using an outdoor cell to serve an indoor user. In such a scenario, the benefits are myriad and shared between the user and the operator: The user experience is dramatically improved, the operator sees huge savings in outdoor system capacity, and it all occurs with more favorable economics compared to traditional small cell strategy.

When selectively deployed alongside home Wi-Fi hotspots, indoor femtocells give the converged operator the chance to capture the majority of indoor traffic with an indoor radio, freeing the outdoor radio to better serve outdoor traffic.

More Discussion to Come

In this post, I talked about the spectral efficiency problems of traditional outdoor small cell deployments and how a femtocell deployment model can address them. Next time, I’ll discuss a total cost of ownership (TCO) model for femtocells over a DOCSIS network, both full-stack and vRAN-based solutions.

And don’t take my word for it! Stay tuned to the CableLabs blog over the next couple months for more discussions about cellular deployments over a DOCSIS network.


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Wireless

Operators Now Have the (ad)Vantage™

Mark Poletti
Director, Wireless Network Technologies

Nov 9, 2018

The first Wi-Fi–certified Vantage™ Access Point device became commercially available last month. This is a milestone because it means the Wi-Fi industry is beginning to incorporate carrier-grade Wi-Fi features into Wi-Fi devices. This will benefit operators’ ability to better manage Wi-Fi networks, which—in turn—will benefit users by delivering an elevated quality of experience.

The Wi-Fi Alliance conceived Vantage™ (the Wi-Fi Alliance’s brand name for carrier-grade Wi-Fi) as a way to provide solutions to operator needs in conjunction with priorities set by Wi-Fi device vendors. Many of the Wi-Fi devices today use IEEE 802.11 features in their baseline design yet implement proprietary features to enhance performance and provide product differentiation. Although this can be beneficial to the user, it can also lead to inconsistent performance if users utilize a variety of Wi-Fi devices with different feature enhancements.

Vantage™ devices attempt to overcome this potential inconsistency by introducing a common set of 802.11 features to meet common operator needs. Such needs include:

  • Enhancements to network connection
  • Connection times
  • Network attachment
  • Faster speeds—most important in high-density, dynamic Wi-Fi network environments that have a high concentration of users.

For example, have you ever experienced slower data speeds on a Wi-Fi network when people exit at a subway station stop? Or lose your connection while waiting at an airport gate when a high volume of passengers deboard? Or find that the text you sent is delayed at a baseball game during the 7th inning stretch?

Vantage™ leverages these key technologies into a single device as a basis for its solution to operator needs:

  • Wi-Fi CERTIFIED™ ac: high-performance, dual-band operation
  • Wi-Fi CERTIFIED Passpoint®: secure, light-touch authentication
  • Wi-Fi CERTIFIED Agile Multiband™: efficient use of spectrum, smart steering
  • Wi-Fi CERTIFIED Optimized Connectivity™: improved roaming, efficient transmissions

Wi-Fi Vantage™ devices offer features that provide automatic, seamless, secure access to Wi-Fi networks and mechanisms for efficient use of spectrum and network resources in densely populated, dynamic environments. It also allows operators to deliver an elevated user experience, increased data rates and the ability to allow more devices to operate on the same network without sacrificing performance. 

CableLabs’ joint leadership with the operator community (mobile and cable operators) created the vision and roadmap for the Vantage™ program while partnering with the Wi-Fi ecosystem. The Vantage™ certification process has been completed, and the operators and industry are now waiting for more Vantage™ Access Points and user devices to become commercially available to improve managed Wi-Fi networks and deliver optimal user experience.

To learn more about Vantage™ in the future, subscribe to our blog. 


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Wireless

Mobility Lab Webinar Recap and Q&A: CBRS Neutral Host Network using Multi-Operator Core Network

Omkar Dharmadhikari
Wireless Architect

Nov 7, 2018

Last week, we hosted the first webinar in our mobility lab series “CBRS Neutral Host Network using Multiple Operator Core Network.” In case you missed it, you can read about the webinar in this blog or scroll down for the links to the video and Q&A.

Background: CableLabs Mobility Lab Webinar Series

The FCC established Citizen’s Broadband Radio Service (CBRS), a 3.5GHz shared spectrum, to alleviate the shortage of frequencies available for wireless communication services. From an operator perspective, propagation characteristics of the CBRS band are a good fit with low-powered small cells, which can provide a capacity boost and fill in the coverage holes for both indoor and outdoor scenarios. With CBRS General Authorized Access (GAA) deployments on the verge of seeing the light by early 2019, wireless operators are investigating ways to utilize newly allocated CBRS band.

Neutral Host Network (NHN) is a CBRS use case which is attractive for mobile operators, cable operators and new entrants because it:

  • Lowers expenses of buying licensed spectrum
  • Lowers investments in building network infrastructure
  • Lowers initial roll-out costs of operating and managing new deployments

With NHN deployments operating in shared spectrum, such as CBRS, there is no need to coordinate radio frequency network planning between the multiple operators sharing the neutral host access network.

Mobility Lab Webinar #1: CBRS NHN Use Case Using Multi-Operator Core Network (MOCN)

Leveraging our in-house mobility lab, we built test setups for several CBRS use cases. The first webinar demonstrates a CBRS use case which utilizes a 3GPP deployment model, called Multi-Operator Core Network (MOCN), where an operator shares its access network and spectrum with other operators. This use case can be a viable alternative to conventional single operator owned network infrastructure.

The webinar provides:

  • An overview of Network Sharing, Active Network Sharing, MOCN and CBRS
  • Description of CBRS NHN use case and its deployment scenarios
  • Lab demonstration of CBRS NHN use case

Our upcoming webinars will showcase the various mobility lab projects we are working on. For any questions, please feel free to reach out to Wireless Architect Omkar Dharmadhikari. You can view the first webinar here and click the link below to download a copy of the Q&A.

Download the First Mobility Lab Webinar Q&A

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Wireless

CableLabs Presents: Mobility Lab Webinar Series

Omkar Dharmadhikari
Wireless Architect

Oct 17, 2018

The CableLabs wireless R&D group has a charter to investigate new and emerging wireless technologies that will benefit our cable operator members, half of which also own mobile networks. As cable and mobile networks continue to converge, we've built a fully functional mobility lab. The aim of the mobility lab is to conduct validation, proof of concept, standards development and new technology assessments to support Multiple System Operator (MSO) use cases.

Mobility Lab Infrastructure

The mobility lab includes a variety of:

  • Radio Access Network (RAN) equipment including Citizens Broadband Radio Service Devices (CBSDs) and small cells operating in licensed bands with FCC approved experimental licenses
  • Multiple cellular virtualized and cloud core network solutions
  • Data Over Cable Service Interface Specification (DOCSIS) backhauled small cells

CableLabs and Kyrio offer a diverse lab environment with an anechoic chamber, shield room, RF tents, UE simulators and a 5,000 sq. ft. test house for testing real-world scenarios.

Mobility Lab Projects

The mobility lab hosts a wide variety of projects spanning from:

  • Low latency backhaul
  • Inter-EPC and PLMN handover
  • Wi-Fi calling
  • 5G converged core
  • LAA and Wi-Fi co-existence
  • Wi-Fi mobility enhancements with ANDSF

The lab is being extensively used for analyzing Over-The-Top (OTT) aggregation solutions for cellular Wi-Fi convergence. We are also working on building test setups for different Citizens Broadband Radio Service (CBRS) use cases that could be important from our members perspective. Recently, we hosted an industry-wide SAS-CBSD interoperability event for the CBRS Alliance that included over 15 vendors and 60 participants to validate the baseline functionality of CBRS.

Want to learn more about CableLabs projects leveraging the in-house Mobility Lab?

We are hosting a “Mobility Lab Webinar Series” to showcase various lab activities and tests performed. The first webinar in the webinar series, “CBRS Neutral Host Network (NHN) using Multi-Operator Core Network (MOCN)”, is scheduled for October 30th, 2018.

The webinar will provide:

  • An overview of network sharing, active network sharing, MOCN and CBRS
  • A CBRS NHN use case and its deployment scenarios
  • A CBRS NHN use case lab demonstration

Stay tuned for information on further webinars in the pipeline. In case of any questions/suggestions, please feel free to reach out to Wireless Architect Omkar Dharmadhikari or the Director of Wireless Mark Poletti. Register for the webinar by clicking below.


Register for the Mobility Lab Webinar

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Wireless

  Better Home Networks: How EasyMesh™ Delivers Intelligent Wi-Fi

John Bahr
Lead Architect, Wireless Technologies

Sep 11, 2018

Today, many people view Wi-Fi as an essential component in their home. However, people routinely experience connectivity issues because networks aren't capable of broadcasting their Internet signal adequately and uniformly throughout their home or business. CableLabs is working with the Wi-Fi Alliance (WFA), and its new EasyMesh™ certification program, to solve this problem and provide extended, uniform coverage throughout your entire home.

Watch our video below to learn about the benefits of Wi-Fi EasyMesh™ and how the certification program will create better home networks by bringing network intelligence to multiple access point (multi-AP) deployments.

Wi-Fi Alliance members are now able to submit their products for testing. Interested in learning more? Read my blog "EasyMesh™ Brings Super Connectivity to Home Networks" and subscribe to our blog.


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