Korea Communication Review January 2015

IN THIS ISSUE

◦ Smartphone penetration (% of population) 79.5%
◦ LTE penetration (% of population) 68.8%
◦ Smartphone subscribers use their phones more than 3 hours a day
◦ LTE traffic represented 94.1% of Korea’s total mobile traffic
◦ Average connection speed (Mobile) 15.2Mbps
◦ Average peak connection speed (Mobile) 41.9Mbps
◦ Broadband penetration rate (% of population) 38.9%
◦ Penetration of FTTH/FTTB+LAN (% of household) 69.8%
◦ Average connection speed (Fixed access) 24.6Mbps
◦ Average peak connection speed (Fixed access) 72.1Mbps
◦ IPTV subscribers 10.1M
◦ IPTV penetration rate (% of household) 55.0%

Korean ICT News • page 2-5
LTE/LTE-A commercialization by South Korea’s big 3 operators • page 8-9
Now giga Internet service available from all the Korean big 3 operators • page 11-13
Debates on LTE-Unlicensed and Wi-Fi (Views of KT, SK Telecom and Qualcomm) • page 29-32
FEATURED ARTICLE: Korean big 3, getting ready for 5G • page 19-27
Sponsor Contents: Ethernet access at 10 Gbps • page 14-17
Quarterly earnings by operator • page 35
Broadband subscribers in Korea UPDATE • page 36-39
IPTV subscribers in Korea UPDATE • page 40-42
LTE statistics in Korea UPDATE • page 43-48
Research and consulting scope of Netmanias • page 54
Average download speed [Mbps] measured by MSIP during Aug. 19 – Nov. 21 2014

© Netmanias Consulting • www.netmanias.com

Korea Communication Review
Publisher/Editor: Dr. Harrison J. Son | son@netmanias.com
Associate Editor: Dr. Michelle M. Do | misun.do@netmanias.com
Advertising Sales: Ho-Young Lee | hylee@netmanias.com | +82-2-3444-5747
Business Development: Steve Shin | cm.s.shin@netmanias.com | +82-10-2884-8870


Korea Communication Review • January 2015

Korean ICT News
Now giga Internet service available from all the Korean big 3 operators
The 'giga Internet era' has just begun,finally offering speeds of 1 Gbps - 10 times faster than the 100Mbps.
For the past 7 ~8 years, the maximum Internet speeds for all access networks (FTTH, LAN and XDSL) have long been 100Mbps.
So, when LTE-A (CA: 150Mbps) was launched in 2013, and when Wideband LTE-A (225Mbps) was released in June 2014, it was shameful for the wired Internet to be helplessly outpaced by the wireless Internet.
Last May, the newly appointed Chairman Chang-gyu Hwang of KT presented a vision of ‘GiGAtopia’ aimed to drastically accelerate wired/wireless access from 100Mbps up to 1Gbps.
On Oct. 20, KT, as the first step of realizing the vision, commercialized the nation's first giga Internet service, soon followed by its competitors, SK and LG U+, in Oct.30 and Nov. 30, respectively.
Read the full article (page 11-13)

Debates on LTE-Unlicensed and Wi-Fi : Views of KT, SK Telecom and Qualcomm
Now, people are talking about LTEUnlicensed. It sure sounds new and interesting. We all know what LTE and Wi-Fi are and how they work.
For LTE, all network operators in the world do their business by paying their local governments billions of dollars of license fees for frequencies, and providing commercial LTE services to their paid subscribers using the frequencies.
On the other hand, for Wi-Fi, nobody needs to pay to purchase frequencies, and anyone can develop a market on their own by taking advantage of the unlicensed frequencies.
Read the full article (page 29-32)

Korean big 3, getting ready for 5G
Definition of 5G has not been clarified yet,but there are some general criteria that makes 5G. First, 5G can support 1,000 times more network capacity than 4G, and provide speeds of 1 Gbps anytime anywhere.
These tremendous improvements in capacity and speed make services for new media like UHD streaming or hologram possible, and require new radio access technologies.
Second, 5G can support a “massive connectivity” technology which would require not high speeds, but enormous connection.
New architecture and technology that can improve efficiency of processing control signaling and support IoT are needed.
In Q4 2014, there were many events in Korea that gave us chances to see how the big 3 see the new 5G era, and how they are getting ready for it.
We will discuss their strategies and technologies for 5G based on the presentations and demonstrations they have given so far in relation to it.
Read the full article (page 19-27)

SK Telecom commercializes world’s first tri-band LTE-A service
SK Telecom Press Release
On Dec. 29, SK Telecom (NYSE:SKM) today announced that it launched commercial tri-band LTE-Advanced (LTEA) service for the first time in the world.
Tri-band LTE-A service offers data speeds of up to 300Mbps by aggregatIng three component carriers in three different frequency bands: 20MHz bandwidth in 1.8GHz band, 10MHz bandwidth in 800MHz band*, and 10MHz bandwidth in 2.1GHz band.
Galaxy Note 4 S-LTE, the first tri-band LTE-A capable device, will first be sold limitedly to a group of consumers who wish to use the service ahead of others and provide feedback on issues including its performance (e.g. speed, transmission stability, etc.) and convenience features.
Through this process, SK Telecom aims to further improve its tri-band LTE-A service to better meet its customers’ needs and provide them with greater value through new mobile value-added services optimized for the ultra-fast tri-band LTEA.
SK Telecom subscribers, including this group of early users, will be able to enjoy the new service at the same price as LTE.

Korean ICT News

Korean smartphone subscribers use their phones more than 3 hours a day.
According to a KT report dated Dec. 15, (Mobile life changes in 5 years since smartphones became available), Korean smartphone subscribers use their phones more than 3 hours a day (app or web usage only, excluding voice call usage).
As of September 2014, daily mobile usage was reported 219 minutes, which was 2.4 times more than 2.5 years ago.
Users spent 15% of the total usage for mobile web surfing and the rest 85% for using apps, and also 57% of the total using Wi-Fi and the rest 43% using cellular data (3G/4G).

Samsung Electronics supplies 'Smart Wireless LAN Solution' to Birmingham Metropolitan College in the UK.
Samsung Electronics (SEC) supplies Birmingham Metropolitan College (BMC), well-known for its excellent training programs in digital technologies, with WLAN APs and WLAN controllers. BMC has about 27,000 students in 8 campuses in Birmingham area.
With the 'Smart Wireless LAN Solution’, students and faculties at the school will be able to use the WLAN at fast and stable speeds without separate authentication or access procedures, even while moving between campuses, starting next year.
The solution is designed to seamlessly provide the best data and voice services even while on the move in school or business environment by taking advantage of SEC’s accumulated know-hows on mobile technologies.
In particular, the latest LTE network technologies like self-organizing network (SON), and radio resource scheduling technology were employed in the solution.
SEC, at the ITU meeting held in Busan last Oct, built a Smart WLAN solution, demonstrating the excellent quality of the solution.

LG U+ demonstrated the world's first ‘LTE-Unlicensed’ capable of 300 Mbps, and aims to commercialize in 2H 2015.
On October 16, LG U+ announced that it successfully demonstrated a new technology 'LTE-U' (LTE in Unlicensed spectrum) that can give transmission speeds of up to four times faster than the current LTE for the first time in the world.
The new technology was implemented by using LTE in 5.8 GHz WiFi spectrum band, and thereby combining the band with the existing LTE's.
In the demonstration, a total of 40 MHz (DL) - 20 MHz of unlicensed 5.8 GHz spectrum and 20 MHz of licensed 2.6 GHz spectrum - were aggregated, achieving a download speed of up to 300 Mbps.
The idea of combining across heterogeneous networks itself is not new.
Previously, demonstrations of aggregation over heterogeneous networks ('WiFi +LTE'), where WiFi signals and LTE signals are combined in a device, have been conducted by KT and also by SK Telecom.
However, what is different with this LTE-U is that it sends LTE signals RIGHT FROM the WiFi band as well, explained the company.
Noticing that the WiFi spectrum, being unlicensed, can be freely used not only for WiFi, but also for any other services like LTE without having to obtain a separate license, LG U+ came up with the idea of LTE-U.
More than 70% of LG U+'s users are subscribing to LTE service, and the number is still increasing. Once LTE-U is commercialized, the company should be able to efficiently distribute everincreasing LTE data traffic by taking advantage of the WiFi band, and also deliver speeds higher than that of LTE only 3-band CA.
The company added that it is commercializing LTE-U as well as 3-band CA, to provide LTE-U service through femto cells for indoor users and 3-band CA service for outdoor users.
The company aims to commercialize LTE-U in the second half of 2015 when LTE-U-ready chipsets are launched in the market.

SK Telecom publishes whitepaper on 5G technology.
On October 21, SK Telecom announced that the company published a white paper on 5G to suggest new direction for technological evolution to 5G, the next generation mobile communications network.
Expecting the era of 5G to arrive in 2020, the white paper outlines analysis, direction and methodologies of 5G network explaining vision, core technologies, services, requirements and spectrum.
Based on its multi-dimensional analysis on 5G network from both user’s and operator’s perspectives, in particular, SK Telecom suggested User Experience, Connectivity, Intelligence, Efficiency and Reliability as 5 Great Values to pursue in the next generation telecommunications technology.
In the paper, SK Telecom anticipates the 5G system architecture to consist of three layers that are service, platform and infrastructure and mapped major technology categories and enabling technologies for each layer. As 5G networkbased services, the paper proposes hologram, immersive multimedia, hyperconnected IoT among others.
SK Telecom’ white paper on 5G technology is now available for download on the company’s website.

DASAN Networks showcases - the world fastest 10G Internet service at ITU-PP.
DASAN Networks has put on display its future Internet technology, developed in South Korea, which is capable of downloading a Full-HD movie in a blink of an eye (0.8 sec).
On October 21, DASAN Networks has announced that it has successfully presented its 10G Internet service using SK Broadband’s service network at BEXCO, Busan in front of the ICT Ministers and field experts on the 20th of October.
The technology that has been revealed, was led by SK Broadband and DASAN Networks as a joint government project to demonstrate ‘10G Future Internet Service.’ DASAN Networks’ 10G EPON equipment performed 10 times faster than the 1G service that we are now growing accustomed to.

Korea Communication Review • January 2015

Korean ICT News

Solbox releases dynamic server-side ad insertion solution 'Ad Zipper'
On November 12, Solbox (Taeha Park, CEO, www.solbox.com), a company specializing in CDN (Content Delivery Network) and cloud technology, today announced its server-side ad insertion solution, Solbox Ad Zipper, capable of easily and dynamically inserting ads into video content on any devices and format.
Ad Zipper was created by Solbox to overcome the limitations of traditional client-side ad insertion solutions.
Keeping to its namesake, Ad Zipper seamlessly inserts ads and video content in real-time on the server side to stitch a single file or stream.
Ad Zipper eliminates data buffering between ads and video content as well as circumvention from ad blockers to provide a smooth TV-like viewing experience.
Ads are easily delivered to new devices without the need for additional development, since they are inserted into video content on the server side without SDKs, plug-ins, or JavaScript that are traditionally required in client-side ad insertion solutions.
Notably, Ad Zipper supports HTTP Progressive Download and HLS (HTTP Live Streaming) for a smooth and reliable ad delivery service with the highest level of device compatibility.
Targeted ads are easily inserted into the desired position with pre, mid, and post-roll formats for maximum viewer coverage.
Solbox anticipates a boost in the quality of viewer experience as well as advertising revenue for OVP (Online Video Platform), CDN, and video service operators through flexible, real-time advertising on all devices with Ad Zipper.
Taeha Park, CEO of Solbox, commented, "Advertising is the main source of revenue in the media industry, and it must be sustained in all emerging devices.
Solbox has studied online content delivery extensively and now offers an evolved advertising services solution with guaranteed quality, convenience, and inter-device compatibility."

According to Akamai's 'State of Internet Report' issued in Sep. 2014, Korea has the highest average connection speed at 24.6 Mbps, and the second highest peak connection speed at 72.1 Mbps, after Hong Kong at 73.9 Mbps.
Also for “4K UHD ready” (>15 Mbps) connection, Korea led the world with unbeatable 62%.
Broadband connection speed [Mbps] % above 15 Mbps Broadband connection speed and % of ‘4K UHD ready’ (>15Mbps) connections by country

MEF Carrier Ethernet 2.0 Revolution seminar (hosted by HFR and SNH) took place in Seoul, Korea on Dec. 10.
This seminar from the MEF brought a new local and global perspective on the world’s most successful network service deployment over the last decade: Carrier Ethernet.
IT features an in depth look at Carrier Ethernet 2.0 (CE 2.0) services, wholesale access services, service management and operations, and its applications in the context of SDN, cloud and mobile backhaul optimization.
Finally, it features the latest on the MEF’s new “Third Network” vision. You can watch all the presentation video clips at Netmanias.com for free.

© Netmanias Consulting • www.netmanias.com
Korea Communication Review • January 2015

Korean ICT News

KT’s GiGA Internet subscription exceeded 100,000 in just two months The subscription of KT’s ‘Olleh GiGA Internet’ is growing steadily since its nationwide commercialization in Oct. for the first time in Korea.
On Dec. 21, KT announced that the subscription of ‘Olleh GiGA Internet’ has continued to grow by more than 7,000 per week since its release on October 20, and exceeded 100,000 in just two months.
‘Olleh GiGA Internet’ offers up to 1Gbps, 10 times faster than the previous 100Mbps, successfully appealing to users who want to enjoy movies, music, UHD contents, etc. fast through the Internet.
There have been lots of positive reviews and feedbacks about the service, especially about its greatly improved speeds, in many online communities.
And also KT’s customer center has received quite a lot of inquiries from potential customers who want to know if the service is available in their home areas or not. According to the analysis of KT’s subscription over the past two months, a great proportion of the subscribers i) are living in apartments in Seoul metropolitan area, ii) use HD, large-volume video contents, and iii) are subscribing to Olleh GiGA Compact (500Mbps) service.
One thing interesting was, over 50% of the subscribers were found to be residents in Seoul metropolitan area.
It was pretty high considering that Internet subscription (of all the big 3) in Seoul metropolitan area accounts for only 40% of the nation’s total.
This result seems to be affected by the fact that there are large-scale apartment communities in Seoul metropolitan area, and thus building necessary infrastructure was relatively easier than other areas.
The analysis also found the data usage of GiGA Internet subscribers was more than 4 times as much as that of non-GiGA Internet subscribers.
These days, large volume HD contents like video have become one of the most basic of all customer needs. This has made fast speeds and reliable quality the key contributing factors to successful customer attraction.
Another interesting finding is the popularity of Olleh GiGA Compact. When KT began GiGA Internet services, Olleh GiGA Internet capable services, Olleh GiGA Internet capable of 1 Gbps was very popular but the popularity declined soon.
And by December, Olleh GiGA Compact (500Mbps) has become more popular, and its subscription accounted for over 80% of the total GiGA Internet service, proving the point that GiGA Internet is not a privilege for some users any more, but a necessity for everyone by now.
KT plans to make more aggressive investment in building GiGA infrastructure in major facilities and apartment complexes by 2016 to make its GiGA Internet service nationwide.

SK Telecom and Ericsson develop Smart Wake-up technology.
On Oct. 30, SK Telecom announced that the company, the company, together with Ericsson, the world-renowned telecommunications technology and service provider, are the first to develop Smart Wake-up, a technology that dynamically wakes up small cells when traffic enters the cell, improving operational efficiency and user experience.
Smart Wake-Up is a new technology to control the operation of idle base stations during late night and early morning.
Through intelligent operation control, the base station will be turned off when no mobile phone is detected within the cell boundary, but if any device comes into the coverage then the base station will automatically sense it and reactivate itself.

What do people use their smartphones for the most? Users in 10~20s use it for communication, music and video, those in 20~30s and 30~40s for web search and games, respectively.
Usage of smartphone and mobile contents varies by age group. First of all, 20-something users stay on their smartphones the longest - 281 minutes a day - among all age groups, followed by the groups of 9 and under, 30-something, and 40-something. The contents used were different by age group too.
In case of mobile games, contrary to expectations that those in their 10~20s would use their smartphones for games most, those in their 30~40s were found to play games with their smartphone the most. In case of communication services (e.g. Kakao Talk), music and video contents, users in their 10~20s spend far more time in such contents than other age groups.
Those in their 20~30s spend more time in web/portal contents than other age groups.

The 'giga Internet era' has just begun, finally offering speeds of 1 Gbps - 10 times faster than the 100 Mbps.
For the past 7 ~ 8 Years, the maximum Internet speeds for all access networks (FTTH, LAN and XDSL) have long been 100Mbps.
So, when LTE-A (CA: 150 Mbps) was launched in 2013, and when Wideband LTE-A (225 Mbps) was released in June 2014, it was shameful for the wired Internet to be helplessly outpaced by the wireless Internet.
Last May, the newly appointed Chairman Chang-gyu Hwang of KT presented a vision of ‘GiGAtopia’ aimed to drastically accelerate wired/wireless access from 100Mbps up to 1Gbps.
On Oct. 20, KT, as the first step of realizing the vision, commercialized the nation's first giga Internet service, soon followed by its competitors, SK and LG U+, in Oct. 30 and Nov. 30, respectively.

▶ Gigabit Internet services by the Big 3
Speed: All three offer both 1 Gbps and 500 Mbps Internet access, and 100 Mbps (existing service) and 500 Mbps/1 Gbps (new giga Internet service) for UTP and fiber subscribers.
Only KT offers 500 Mbps service (G.hn-based) to phone line subscribers (existing VDSL subscribers).

Price Plans: All offer fixed rate plans. With 3-year commitment, \30,000 for 500 Mbps and \35,000 for 1Gbps, which are respectively \5,000 and \10,000 more than the existing 100Mbps.
Each offers different discount rates for bundling with phone, IPTV, etc. (see their websites for details).

To control heavy users' oligopolistic usage of bandwidth, big 3 impose a speed restriction of 100 Mbps on a heavy user whose daily usage reaches 100 GB, for the rest of the day.
SK Broadband

And the other thing is that both Internet and IPTV traffic are delivered to the access or backhaul network, through the same link, and this is the case for all three operators.
As a result, Internet traffic speeds can be badly affected in some areas, dropping far below 1 Gbps, because of the IPTV traffic with higher QoS. So, additional investment to address this issue should be followed as well.
So far, giga Internet has not presented any captivating killer application yet. Instead, it has been appealing to users through mere speed competition, giga WiFi service, offering quality video for home users with multiple IPTV services, etc.
The Big 3 are currently focusing on R&D to introduce new killer applications of giga Internet, and are expected to present new giga Internet-based services next year.

Giga ONT specification: For FTTH, ONTs are introduced at home. Recently-released ONTs support 1Gbps, and Internet speeds can be easily upgraded to 500Mbps or 1Gbps simply by switching the setting to ONT or OLT.
Of course, those released earlier must be replaced by new ONTs. KT and SK use a type of ONT that has 4 GE ports (UTP), connecting to up to 4 PCs.
To each PC, a public IP is assigned (bridge mode). For now, installation of a separate AP is required on this type of ONT to use giga WiFi service.
But, a giga WiFi ready ONT is under development, and expected to be available for home installation in 2015.
Additional services: Giga Internet service subscribers of the big 3 can use giga WiFi service (802.11ac, 300Mbps), with or without charge, depending on the package they selected.
KT and SK are working on development of the commercial service version of a giga WiFi AP for home users, which is expected to hit the market in early 2015.

▶ How did the market react?

KT, who commercialized the service first back in Oct. 20, has been gaining customers fast. The company said at the 'Network KOREA 2014 Workshop' held on Dec. 12, "When we began the service, our goal was to attract 50,000 new customers by the end of the year.
But, the number reached 30,000 in just one month, and 93,000 in 8 weeks. And it is predicted to exceed 100,000 by the end of the year."
Although marketing for the service has been done on restricted service areas only since its release in Oct., the subscription for the service was more than 6 times the monthly average of the existing non-giga Internet service.

▶ What to do now?

KT said, "Since the release of the giga Internet service, there has been increase in average traffic of our services. 500Mbps GiGA Compact subscription was twice as much, and 1Gbps GiGA Internet subscription was 6 times as much of the 100Mbps subscription."
The subscription growth for the giga services and the resulting traffic increase have been much stronger than anticipated. In response, KT is planning to increase the network capacity. Particularly, because quite a lot of OLTs have still 1GE or 2x1GE in uplink, investment for upgrading to 10GE should be made.
The company's competitors, SK and LG U+, are facing the same issue as well.




Executive Summary
The Metro Ethernet Forum (MEF) has defined and promoted Carrier Ethernet, a set of Ethernet-based carrier services.
These services allow subscribers such as enterprises, research institutions, schools, and wireless carriers to achieve Ethernet-based connectivity over a wide-area network.
Network Interface Devices (often called NIDs) are becoming the norm at the User-Network Interface (UNI) between Customer Equipment devices and the Carrier Ethernet network. The NIDs provide many important functions necessary for successful management and operation of the Carrier Ethernet service.
It is becoming increasingly common and desirable to use 10G Ethernet at the UNI and this calls for a new breed of 10G capable Network Interface Devices that can provide all of the necessary NID functions with 10G interfaces as reasonable cost.

10G Is Now Where It’s At!
Now, 30 years later, Ethernet is the data link of choice for all LANs and an increasing number of WANs.
10Gbps Ethernet (one thousand times as fast as the original 10Mbps Ethernet) is fast becoming the client/UNI connection of choice driven by the need for increased bandwidth and the fact that 10G is the most cost effective wavelength on a DWDM fiber.
1G wavelengths can go farther than 10G wavelengths (roughly 150km vs. 80km), but the facility cost is the same—the cost of a single wavelength (color) on a fiber that can carry 80 or 96 colors. 10G transceivers and 10G switch interfaces cost a little more than 1G but this difference is a one-time cost and it is shrinking.
There is no recurring cost difference. Electrical power used by a 10G interface is only a few percent more than the power used by a 1G interface.
Then there are 40G and 100G Ethernet. 40G Ethernet appears to have a home inside the datacenter but not in the wide area. 100G is becoming increasingly popular for connections inside carrier networks but is still too expensive for client connections.
Ethernet Service Providers are deploying switches with 10G interfaces as the cost differential drops. In many contemporary switches a 10G interface can also be configured to support a 1G interface so they are both future-proof and flexible.
Clearly, there are many client services that have very small bandwidth requirements, e.g. 10Mbps or 50Mbps.

The Metro Ethernet Forum (MEF) has been working since 2001 to create an industry-wide framework that fosters the deployment of carrier-based Ethernet services.
With over 200 members, split between carriers and equipment vendors, the MEF has focused on five attributes that are needed to enable Carrier Ethernet.
Carrier Ethernet is based on a set of subscriber services, E-Line (point-to-point), E-LAN (multipointto-multipoint), E-TREE (rooted multipoint) that are delivered to the subscriber at a reference point called the User-Network Interface or UNI.
The subscriber (customer) side of the UNI is called the UNI-C and the network operator side of the UNI is called the UNI-N.
For those, it doesn’t really matter what the UNI physical interface is. But if bandwidth requirements exceed 100 or 200Mbps, and are growing, then using a 10G UNI makes a lot of sense and will avoid a reconfiguration down the road.
Many providers such as Verizon, AT&T, Comcast, Windstream, etc. have been offering 10G UNIs.
They are reacting to the explosion in Ethernet Service deployments and the increasing bandwidth required by these services. In 2013, OVUM (www.ovum.com) estimated Carrier Ethernet service revenue to be approximately $35B.
They projected Ethernet Services Growth (Source: OVUM) growth to $62B in 2018, 35% at 1G and 25% at 10G.

Traffic shaping is a traffic management function that smooths out bursty traffic so that the network operator’s traffic policer will accept more of the traffic as conforming to the specified bandwidth profile.
The traffic shaper builds a queue of packets and schedules the transmission of each packet to match the traffic parameters specified in the provider’s bandwidth profile.
Although not a requirement, traffic shaping is a recommended function and is discussed in an appendix to MEF10.3.
If the CE does not support these functions, the Ethernet Service can be deployed, but it is much harder to guarantee the reliability and performance of the service.
NIDs to the rescue!
Network Interface Devices (NIDs) solve the problem. They serve the dual purpose of providing the demarcation point between the subscriber and the network operator, and at the same time they act as an extension of the Customer Equipment to provide the important OAM and shaping functions.
New 10G NIDs such as the HFR HA-805 provide these functions and each interface supports both 1G and 10G Ethernet. They can be used to provide 10G access to the Carrier Ethernet network even if the CE device has only 1G interfaces.
These devices provide important benefits to the subscriber. They are monitoring the end-to-end Ethernet Service both for faults and for performance, so they can provide fast reporting and response Customer Equipment Requirements.
The challenge for subscribers is that most Customer Equipment (CE) does not support the functions necessary for successful connection to the Carrier Ethernet network. Three important functional requirements are: 1. Link OAM (from IEEE 802.3) 2. Service OAM 3. Traffic shaping
Link OAM is a low-level protocol defined by IEEE 802.3 for link-level monitoring on a point-to-point physical Ethernet channel. It provides procedures for information exchange, reporting of critical Ethernet link events, and loopback.
Link OAM support is a requirement for UNI type 2.2 (MEF20).
Service OAM is a broad set of processes for Fault Management and Performance Monitoring. The protocols are defined in IEEE 802.1Q(ag) and ITU-T Y.1731 and their application to MEF-based Carrier Ethernet services is defined in MEF17, MEF30, and MEF35. The CE is required to support multiple maintenance sessions, one for the UNI itself, one for each Ethernet Service that terminates on the UNI.
Also, a TEST session that can be setup from the UNI-C to any point in the network, when needed, to isolate/debug faults. Service OAM support is a requirement for UNI types 2.1 and 2.2 (MEF20).

Summary
MEF-based Carrier Ethernet services are broadly available. As of mid-2014 there are 135 CE2.0 certified services available across 20 countries. Traditional enterprise applications such as file storage and backup and database access are requiring more and more bandwidth.
New applications such as document imaging and medical imaging require even more.
Therefore, there is a strong move to deploy 10G Ethernet for access connections. The additional investment is small and the growth potential and peaceof-mind is great.
Ethernet Access Devices not only provide the necessary functions to ensure a reliable Ethernet Service deployment but the new generation of 1G/10G EADs can also ease the migration to 10G Ethernet, offloading both the functionality and the performance requirements from the Customer Equipment.
Ethernet Service both for faults and for performance, so they can provide fast reporting and response to both connectivity and performance problems. And since they reside at the subscriber’s location, their domain includes the access connections to the provider’s cloud.
The new generation of 10G NIDs are powerful enough to handle the demanding job of forwarding tens of millions of packets per second, and at the same time these quiet/fanless devices are physically small, and draw a small amount of power.


So, KT's presentations on 5G have been, from the perspective of GiGAtopia vision rather than 5G technologies, focused on convergence services to be provided when GiGA infrastructure (wired and wireless) is secured.
It looks like KT, without a clearly established concept of 5G available yet, wanted to first develop 5G platform and convergence services based on the wired GiGA infrastructure, and then expand them to the wireless infrastructure once 5G becomes commercialized.
The Chairman Chang-gyu Hwang, newly appointed in May 2014, declared "GiGAtopia" as KT's new vision, which consists of the three layers: GIGA Infra, GiGA Platform, and Future Convergence Services
· To transform the existing wired and wireless infrastructure into GiGA infrastructure for provision of giga-class speeds
· To build an open GiGA platform by standardizing the existing platform features
· To provide various future convergence services on the new platform
We will discuss how KT defines 5G and 5G infrastructure based on GiGA infrastructure.

1.1 GiGA Infra (GiGA speeds available in wired infrastructure since 2014, and 5G to be available in wireless infrastructure) Mr. Seong-mok Oh, the head of the Network Business Division at KT made a note on GiGA infrastructure at a forum titled "the 20th Anniversary of Commercialization of the Internet in Korea and the Giga age", saying "The goal of KT is to deliver UHD streaming contents through wired/wireless networks capable of supporting 1 Gbps-class speeds.
So, we aim to accelerate wireless access speeds to 1 Gbps, and to make all the wired access 100% giga-class by 2018 (revised to by 2019 according to KT's presentation at 'Network Korea 2014' conference in December).
The GiGA infrastructure consists of wired and wireless GiGA infrastructures. In the wired infrastructure, the giga era has already begun when GiGA Internet service was commercialized in Oct. 2014. GiGA Internet now provides 1 Gbps through GiGA FTTH network, and up to 500 Mbps still through copper cables even for old houses.
KT plans to expand GiGA Internet to other major cities and areas by 2016, subscription, LTE-A was commercialized for the first time in the world.
Here are some facts about Korea's LTE. As of December 2014, i) Korea recorded an LTE subscription rate of unbeatable 62% as LTE is reaching maturity, and ii) LTE traffic - about 108,792 TB - accounts for 94.5% of the total mobile data traffic of the nation.
By 2016, the LTE subscription rate is expected to reach 80%, and the LTE traffic, is also expected to grow drastically. In response, the Korean big 3 operators are making efforts to increase network capacity through LTE/LTE-A optimization and small cell introduction, and to achieve a goal of commercializing 5G by 2020.
Definition of 5G has not been clarified yet, but there are some general criteria that makes 5G. First, 5G can support 1,000 times more network capacity than 4G, and provide speeds of 1 Gbps anytime anywhere. These tremendous improvements in capacity and speed make services for new media like UHD streaming or hologram possible, and require new radio access technologies.
Second, 5G can support a “massive connectivity”technology which would require not high speeds, but enormous connection.
New architecture and technology that can improve efficiency of processing control signaling and support IoT are needed.
In Q4 2014, there were many events in Korea that gave us chances to see how the big 3 see the new 5G era, and how they are getting ready for it.
We will discuss their strategies and technologies for 5G based on the presentations and demonstrations they have given so far in relation to it.

5G Strategies by the Big 3

1. 5G Strategies by KT
KT is the No. 1 wired and No. 2 mobile operator in Korea, and has the most powerful wired and wireless integrated networks. The company does not see 5G network as its next generation network itself, but as just one of the components that comprise its GiGA infrastructure required in GiGAtopia, its newly presented vision.
That is, it sees 5G network as a wireless GiGA infrastructure in the future.
Mobile speed and QoE are to be improved continuously through further advancement of LTE until a nationwide 5G network is finally launched. KT's 2015 plan to make LTE more advanced includes i) implementing new features in 3GPP Rel.12, and ii) reinforcing the current network capacity. For developing new Rel.12 features, KT will implement features such as Uplink CA (50 ~ 100 Mbps), LTE-Direct (Device-Device, Device-DeviceeNB), and dual connectivity for seamless communication environment.
And for reinforcement of its current networks, it will i) commercialize and expand 3-band CA major cities and areas by 2016, and to build a fullyfledged wired GiGA infrastructure by achieving 100% GiGA Internet service in 2019.
In the wireless infrastructure, on the other hand, the maximum speed as of Dec. 2014 is just 225 Mbps, provided through 2-band CA2, an LTE-A technology.
But it will be improved up to 300 Mbps through 3-band CA3 commercialization next year. To evolve into a wireless GiGA infrastructure, KT is planning to i) continue to improve LTE-A performance, ii) offer multi-RAT CA that combines LTE and GiGA WiFi, and iii) ultimately provide 1 Gbps through 5G radio access technology in 2020.
Figure 1. 5G in KT's GiGAtopia
(Source: KT's '2014 Net Trend Conference' presentation materials - Re-illustrated by Netmanias)

KT's 5G network will be migrated from its LTE network with SW-based control and new 5G radio access technologies. Its 4G will co-exist with 5G for a long time, and in the 5G network, various access technologies such as D2D, IoT and mmWave will be integrated.
5G radio access: 5G radio access technologies refer to innovative technologies, based on mmWave and a new type of HetNet, designed to provide satisfying 5G performance. mmWave 5G access is used at small cells operating at new higher frequency bands (i.e., mmWave bands).
And the new HetNet-based 5G access will allow for hybrid access - enabling devices to access not only the small cells operating at higher frequency bands, but also the macro cells operating at existing lower bands.
expand 3-band CA to achieve higher maximum speeds in high-density areas, ii) improve weak electric field coverage for minimized VoLTE shadowing using 900MHz band and repeaters, iii) install more small cells (outdoor femto cells) for enhanced QoE, and iv) commercialize Multi-Path TCP (MPTCP)-based LTEWiFi aggregation for better QoE.

5G Requirements and Target Value
At a KRnet 2014 panel session, Hyun-pyo Kim, a Vice President at KT, defined the company's 5G network requirements and target values as seen in Table 1 below.
Also, noting that the existing architecture cannot satisfy "Flexibility/Low-cost" requirements in 5G networks, where small cells operating at several ~ dozens of GHz will be deployed, he emphasized the necessity of employing SDN/NFV to introduce an innovative wireless network architecture.

Table 1. KT's 5G requirements and target values (source: KT)
converged. To this end, the company will: i) secure 5G network that can take care of ultra high speed and massive connectivity (IoT).
ii) build an intelligent SW platform based on realtime analysis of big data and virtualization.
iii) provide ICT convergence services by taking advantage of innovative UIs and HD multi-media.
SK Telecom, while focusing on 5G network, is taking the first step for realizing ICTnomics. It disclosed its plan to take a lead in developing 5G technologies, and to commercialize 5G network in 2020 for the first time in the world, pursuing technology differentiation strategy in 5G access technologies realizing 'giga mobile' speed.
Previously (in 2G, 3G and 4G), existing networks have been replaced when new next-generation networks were introduced (i.e. 3G network replaced 2G network).
5G network, however, is expected to co-exist with LTE network through cooperating, instead of replacing, with it.
In 5G, even when new innovative technologies are introduced providing mobile giga speeds and massive connectivity, LTE technologies are expected to continuously evolve, allowing 5G revolutionary technologies and various access networks to be integrated based on LTE networks. Figure 2 shows the company's evolution and revolution paths toward 5G.
SK Telecom commercialized the world's first LTE-A network by introducing carrier aggregation (CA) back in June 2013. In 2014, small cells were introduced in the LTE-A network, which made the network begin to evolve into one with C-RAN based HetNet architecture.
SK Telecom plans to commercialize 3-band CA in 2015, and ‘SUPER Cell’ technology featuring inter-cell coordination in HetNet in 20164. Key features of ‘SUPER Cell’ like Elastic Cell are expected to be further optimized, and employed as fundamental technologies in 5G as well.
The company is planning to demonstrate 5G network during Pyeongchang Winter Olympic in 2018, and launch the world's first 5G network by 2020.


1.2 GiGA Platform
KT is pushing forward a plant to build an open GiGA platform to provide various future convergence services on GiGA infrastructure. The GiGA platform will be based on IoT, new media, cloud and big data analysis, and designed to integrate various radio accesses.
1.3 GiGA Service (Future Convergence Service)
KT has identified key services that can create synergy between communication and other industry by taking advantage of GiGA infrastructure, and defined them as the "5 future convergence services": smart energy, integrated safety, next-generation media, life-enhancing care, and networked transportation.

Pre-5G Displays and Demonstrations
At '5G Global Summit 2014', KT demonstrated vEPC and vIMS, virtualization technologies for mobile core network and services, by using prototype. And at 'World IT Show (WIS) 2014', it conducted demonstrations of GiGA Infrastructure technologies like 1G/10G GiGA Internet, LTE-A 3CA, and GiGA WiFi technologies.
And it presented ICT convergence services like KT-MEG (ICT+Energy), GiGA lab (ICT+BT), eyewire game (ICT+Healthcare), GiGA baseball (ICT+Sports) and GiGA island, GiGA safety, GiGA home, and also hosted a K-live concert featuring hologram as a nextgeneration media service.

2. 5G Strategies by SK Telecom
Immediately after KT announced its new vision GiGAtopia in May, 2014, SK Telecom, the No. 1 mobile operator in Korea, also presented ICTnomics (ICT + Economics) designed to integrate ICT into a wide range of industries as the core concept of its 30-year growth plan.
The company announced its plan to i) commercialize 5G network in 2020, and ii) develop services in which ICT technologies and industry are converged. To this end, the company will:

Enabling Platform: 5G platform i) features Network-as-a-Service (NaaS) which allows for configuration and change of telecommunications and service functions by using virtualized SW on programmable HW, ii) provides open API to use SK Telecom's services, and iii) is an SW-based platform, with a built-in intelligent engine capable of big data analysis, that is managed through orchestration and SDN control.
Innovative Service: SK Telecom, pursuing a differentiation strategy through 5G technologies, is focusing on provision of visual experience that has no burden of time and space restrictions and on IoT.
Services like mobile UHD, AR/VR, remote healthcare, mobile hyper-cloud, immersive communication (e.g., hologram), and massive connectivity-based IoT service are defined as key 5G services.

5G System Architecture

SK Telecom's 5G system architecture consists of the three layers: Service, Platform, and Infrastructure.
Hyper-Connected Infrastructure: This network infrastructure can serve various types of devices and support ultra-high-speed data delivery.
To realize this high performance 5G infrastructure, SK Telecom aims to enhance capacity and frequency efficiency, expand frequency bandwidth, and improve operation efficiency.
Up to 4G, communication between device and base station was 1:1 communication. In 5G, however, network connectivity has been enhanced, allowing for communication between devices, base stations, or between licensed and unlicensed bands.

3. 5G Strategies by LG U+

LG U+, acknowledging service as a more important factor in 5G than speed, is putting more efforts into developing differentiated services than mere technologies competition. That is, it is taking a stance that it would develop 5G services first, and then take care of technical matters later.
LG U+, the No. 3 mobile operator in Korea, had skipped a generation (3G) and leaped from 2G (CDMA) to 4G (LTE) when it first launched 4G. So, for LTE subscribers, the LTE network 5G Major Technologies Table 4 lists the major 5G technologies defined by SK Telecom.
It includes evolutionary technologies that can be commercialized in LTE-A as well and revolutionary technologies that can only be commercialized in 5G.
New radio access technologies (e.g., advanced IoT and new waveform/duplex) are two of the most representative 5G-specific technologies.

Pre-5G Displays and Demonstrations

SK Telecom presented pre-5G technologies like Pre-5G testbed, LTE FDD/TDD CA, vRAN, SDN and NFV, and distributed 5G white paper at ‘5G Global Summit 2014’.
At ‘WIS 2014’, the company demonstrated 5G technologies like mmWave communication and quantum cryptography technology, and presented various ICT convergence technologies.



5G Framework
LG U+’s 5G framework is customer-centric. LG U+ saw safety improvement, cost saving, time management, and emotional care, rather than high-quality communication such as high speed/low latency, as the values that 5G can provide to customers. LG U+ regards 5G infrastructure not only as transport network but also as enabler.
5G infrastructure and contents identify a customer's personalized values through analyzing the usage patterns of the customer, and provide a feedback in real time. The quality of such personal assistant service lies on the accuracy of the big data analysis.

Closing

The Korean big 3 have their own advantages in the coming 5G era. SK Telecom is the No. 1 mobile network operator and thus is at an advantage in radio access technology.
KT, the No. 1 wired network operator, is at an advantage in building a wired and wireless integrated network. LG U+ has the strengths in that it has been most aggressive in developing differentiated services/plans as the last player who joined the race.
Through this presentation/demonstration, we have looked into the big 3's strategies on 5G. We learned SK Telecom is focusing on taking a lead in 5G technologies capable of giga mobile speed while the other two are focusing more on services than technologies.
KT, based on its wired and wireless integrated networks, is making efforts in developing IoT-based convergence services.
LG U+, on the other hand, is paying more attention to development of subscribers, the LTE network was the only channel that it had to provide voice service through.
The company, more eager than any of its competitors to have an LTE network, built the world's first nationwide LTE network.
It has vigorously attempted to develop differentiated services (mostly video services), and introduced an unlimited LTE plan for the first time in Korea. As users' life style changed from voice-orientated to video-orientated, LG U+ could get the LTE service rolling.
More and more of 2G/3G frequencies are now being switched to LTE's. And this puts the company, with relatively less frequency than its competitors, at a disadvantage in speed competition where it should be more dependent on bandwidth.
So it would be difficult for the company to optimize the LTE network AND develop 5G technologies all at the same time.
LG U+ expects there will be some factors that would affect users’ life style in 5G just like there were in LTE.
As the technological details of 5G have not been clarified yet, the company seems to plan to focus on development of new services for a while, and then to work on 5G technologies once clarified.


Rude LTE vs. Polite WiFi
WiFi access is based on carrier sensing, and thus provides a connection-less service without dedicated connection. So, it is like a one-lane road.
A user can be served only when no other user is being served. On the contrary, LTE access, based on scheduling, provides a connection-oriented service with dedication connection.
So, like a multi-lane road, it allows multiple users to be served at once.
Due to different efficiency of two types of access, WiFi guys are worried that if unlicensed band is shared by both WiFi and LTE concurrently, all the transmission opportunities would be hogged by LTE.
So they insist Listen Before Talk (LBT) regulation should be applied to make sure carrier sensing is performed also for LTE in unlicensed band, before data delivery.

Earlier in September, the 3GPP RAN plenary meeting approved Licensed-Assisted Access using LTE (LAA) as a Study Item (SI) of Release 13.
This approval provoked active discussion on how to use unlicensed band for LTE service. The target band was 5 GHz. The SI work is to be completed by next June, and its standardization is to be finalized by the end of 2017.
As discussion on LAA (or LTEUnlicensed (LTE-U) as called in this post) gets heated, LTE advocates welcomed the news, but Wi-Fi advocates expressed their concerns.
LTE advocates seem delighted by the fact they can have more frequencies available for FREE. Especially to those operators who have been under pressure of lowering data plan rates despite the ever-soaring traffic, it certainly was a tempting idea although they, trying to find out the intention of the government who actually manages radio resources, seem to try to look nonchalant about the news.
On the other hand, Wi-Fi advocates are concerned about possible degradation of Wi-Fi communication which may be caused when unlicensed band is shared by Wi-Fi and LTE services, and thus data transmission opportunities are hogged by LTE. For
LTE service, carrier sensing is not required. But Wi-Fi service requires channel sensing to make sure no other user is using the same channel. This puts Wi-Fi at a big disadvantage at the transmission opportunity battle.
The LTE advocates, aware of this issue, claimed that they can come up with a win-win solution that would allow both LTE and Wi-Fi to coexist, and share unlicensed band harmoniously, and fairly.
But, it does not sound convincing enough to assure the other party.
In order for LTE and Wi-Fi to be able to coexist, issues relating to the governments' frequency management/policy as well as technical issues should be addressed.
This is because each country has technical issues should be addressed. This is because each country has different Wi-Fi bands and radio

Now, people are talking about LTE-Unlicensed. It sure sounds new and interesting. We all know what LTE and Wi-Fi are and how they work.
For LTE, all network operators in the world do their business by paying their local governments billions of dollars of license fees for frequencies, and providing commercial LTE services to their paid subscribers using the frequencies. On the other hand, for Wi-Fi, nobody needs to pay to purchase frequencies, and anyone can develop a market on their own by taking advantage of the unlicensed frequencies.
Also from a user's perspective, the difference between the two is clear - you pay for LTE service, but not for Wi-Fi.
So, Wi-Fi has been more attractive to users. As network operators are becoming more interested in this unlicensed frequency bands, the past two years have witnessed some territorial disputes between the two.
In Korea, LG U+ demonstrated LTE-U last month, and announced its plan to commercialize the service next year. Having developed a sudden but keen interest in this matter, Netmanias made a visit to "LTE-Unlicensed and Wi-Fi Workshop" held by the Korean Institute of Communications and Information Sciences (KICS) on November 12, and would like to share what we learned and heard from the operators, vendors, labs/research centers, etc. with our readers.

regulatory requirements on 5 GHz unlicensed band. To make 5 GHz Wi-Fi band global, global harmonization may be needed - Wi-Fi band allocations should be adjusted and technology standards should be revised accordingly.
We will have to wait and see whether this LTE-U can be a potential for LTE advocates but a potential concern for Wi-Fi advocates, or it can be a win-win solution for both sides.
3GPP LAA (Licensed-Assisted Access using LTE) Then, what is LAA that 3GPP approved in September? LAA is a new technology that combines a LTE licensed band and an LTE unlicensed band using carrier aggregation (CA), while still anchoring off licensed band.
So, UE will always attach to a licensed band to access its network for services, and eNB will offload traffic in the licensed band to the unlicensed band through CA of the two bands depending on the conditions at eNB.
During CA, the licensed band works as an anchor, serving as a Primary Cell (PCell) while the unlicensed band serves just as a Secondary Cell (SCell).
That is, the unlicensed band can only be activated through CA, and cannot be involved in LTE communication independently. The key issue with LAA is Wi-Fi-LTE coexistence in unlicensed band.
Design targets and options for LAA operation are to be defined considering the regulations on 5GHz band.
The figure below illustrates three CA types to be discussed here. (a) Using existing licensed bands (b) Involving inter-Radio Access Technologies (RAT)
(c) Using licensed and unlicensed bands as discussed in LAA

Korean Operators' Position SK Telecom and KT, who both have just started LAA, are taking the same wait-and-see stance in general, but slightly different stances depending on how strong their Wi-Fi/small cell infrastructures are.
KT, with the most powerful Wi-Fi infrastructure in the nation and also high Wi-Fi offloading rates, was more interested in protection of Wi-Fi users.
On the other hand, SK Telecom with the most LTE Femto cells apparently showed more interest in the idea of taking advantage of taking advantage of new band that LTE-U may give.
KT
As the No. 1 wired and No. 2 mobile network operator in Korea, KT has been building a carrier Wi-Fi infrastructure most extensively, and also making significant efforts for research and development of multi-RAT CA solutions that combine LTE and Wi-Fi networks.
As a result, Always Best Connected (ABC), an App-based combining technology, has already been adopted in its “Olleh TV Mobile” App, and IP Flow Mobility (IFOM), a network-based combining technology, was demonstrated late last year.
Multi-Path TCP (MPTCP), another network-based combining technology, is currently under review.
However, when it comes to LTE-U, KT does not have a clear plan yet because discussion about the standardization of this new concept has just begun, each country has different regulations on 5 GHz band, and their policies on LTE-U are yet to be determined.
Dr. Seongkwan Kim at Spectrum Strategy Department of Network Business Unit who spoke for the company at the workshop noted "We believe our Multi-RAT CA solutions
are more technically mature than LTEU.
But, we expect the two to be complimentary, reflecting trends in the market and user preference in the near future." According to the data released by KT, Wi-Fi users have already been quite dissatisfied despite the company's extensive carrier Wi-Fi infrastructure. So, if LTE-U begins to use unlicensed band, the dissatisfaction will only grow more.
At the workshop the company, with the most Wi-Fi users among the big 3, strongly suggested, for protection of these users, (i) to adopt Listen Before Talk (LBT) in the nation's unlicensed band, (ii) to recommend use of predefined channels in 5 GHz band as in 2.4 GHz band, and (iii) to develop a technology that can assure fairness between current Wi-Fi users and LTEU users.
KT said it prefers multi-RAT CA for now. But once LTE-U is standardized and regulation issues are taken care of, the company is expected to introduce LTE-U primarily in LTE Femto first, and then gradually switch its traffic offloading base to LTE-U.
With the commercialization of GiGA Internet in last October this year, KT has been upgrading its Wi-Fi infrastructure to giga-class. So, it should be able to efficiently support traffic offloading caused by LTE-U.
KT also predicted that, once introduced, LTE-U and multi-RAT CA would work in a way that is complementary, reflecting specific market circumstances and user preference.
LTE-U may be more efficient in terms of frequency efficiency and mobile access reliability, but multi-RAT CA can still be preferred according to availability of LTE-U mobile devices, favorable pricing policies, etc.
As LTE-U alone cannot access unlicensed band, it would still need to work with Wi-Fi.

SK Telecom

Dr. Tak-ki Yu at Network Technology R&D Center of SK Telecom said "We are also getting ready for LTE-U, but at R&D level for now".
The company, Korea's No. 1 mobile network operator, has much more mobile traffic and subscribers than its competitors, and thus has been struggling with the frequency shortage issue.
For such reason, it has been wanting to offload LTE traffic more than anyone else.
It seemed he wanted to put it as R&D-level preparation for now because the official LTE-U policies are not announced by the government yet.
Apparently to the company, the chance of obtaining new frequency band is definitely a good news, and it is expected to take full advantage of the new band.
In July this year, SK Telecom demonstrated multi-RAT CA that combines LTE and giga Wi-Fi by using MPTCP although multi-RAT CA does not seem to be the company’s preferred approach.
While KT has focused on traffic offloading through Wi-Fi by expanding/reinforcing its carrier Wi-Fi, SK Telecom has done the same through building Femto cells.
At MWC 2014, SK Telecom presented LTE-A Femto cells featuring 2-band CA technology, which it aims to commercialize next year.
Earlier in October, it also launched the giga Internet service, joining KT. And this will help to improve performance of the Femto cell infrastructure.
SK Telecom is expected to perform CA using licensed band by mostly using LTE-A Femto cells until LTE-U standardization is completed, and then adopt LTE-U once the LTE-U standards are finalized.

LG U+

Unfortunately LG U+ did not participate in the workshop and so we could not hear from them directly. It was LG U+ who conducted LTE-U demonstration earlier in October and announced the plan for LTE-U commercialization in 2015, provoking controversy on LTE-U.
During the demonstration, it realized a speed of 300 Mbps through CA of a total 40 MHz (20 MHz in licensed 2. 6 GHz band and another 20 MHz in unlicensed 5.8 GHz band).
Many people at the workshop were eager to hear from LG U+ about its position on this hot topic, LTE-U. Probably the company was not ready to answer all the questions expected at the workshop, or did not want the new technology to be disclosed yet.
At 5G Global Summit held in Busan last month, we personally asked a question to one of the LG U+ personnel there about the company’s plan for LTE-U commercialization in 2015. He neither confirmed nor denied the plan. It looks like the company plans to begin the service in a restricted area, even before finalization of LTE-U standards, by implementing LTE-U as a proprietary technology to be applied to LTE-U standards, and then to upgrade it by applying the standardized technology once standards are finalized.

Discussion on Regulatory Requirements
In order for LTE-U to work, not only the foregoing technical issues, but also issues arising from different frequency management/policies for different countries should be taken care of first.
Each country has different Wi-Fi frequency band allocations in 5 GHz and different technology standards to follow.
Korea’s technology standards are Shown in table 1.
Currently Korea has 24 Wi-Fi channels (20 MHz each) in 5 GHz band, and 19 of them are nonoverlapping channels. According to Dr. Seung-Keun Park at ETRI, with the current channel configuration, LTE-U can be enabled only in four channels (5.15 ~ 5.25 GHz bands), and not in any other bands - there is no commercial chip that supports DFS in either 5.25 ~ 5.35 GHz band or 5.47 ~5.65 GHz band, and OFDMA is not allowed in 5.725 ~ 5.825 GHz band.
So, to use LTE-U in 5.725 ~ 5.825 GHz band, technology standards must be amended first to allow OFDMA for communication.

Who are LTE advocates then? Mostly network operators and vendors. At the workshop, vendors like LG Electronics, Samsung Electronics and Qualcomm shared their views on the issue.
The key benefits of LTE-U they pointed out can be summarized as follows:
1. Frequency efficiency: Unlike Wi-Fi which allows only one user to communicate at once through carrier sensing, LTE-U can give higher frequency efficiency as it allows multiple users to communicate at once, and it is highly interferenceresistant
2. Economic feasibility: It can take advantage of free frequency and the current LTE network
3. User experience: Quality of user experience to be enhanced by LTE

QoS technology

Qualcomm proposed an algorithm called Carrier Sensing Adaptive Transmission (CSAT) for fair coexistence with Wi-Fi in co-channel.
CSAT has LTE-U on/off feature – LTE-U is used if LTE-U is on, and Wi-Fi is used if it is off.
The company presented a test result showing that when LTE-U is on, LTE-U performs two times better than Wi-Fi, and when LTE-U is off, Wi-Fi performance is not affected.
Lots of interests as well as concerns, and even objections, were expressed regarding this proposal. Professor Sunghyun Choi at Seoul National University pointed out the on/off feature may provide the same Wi-Fi performance in terms of throughput, but Wi-Fi performance would drop drastically while LTE-U is on.
As a result, the quality of delay-sensitive service like VoIP would be affected inevitably.
Wi-Fi guys have something to say too. They want certain etiquette to be observed in unlicensed band, and LBT to be included in LTE-U standards.
They demand, in unlicensed band, LTE-U also perform carrier sensing for opportunistic delivery.
Noting that, in a country with no LBT regulation, LTE-U service can be launched even before LTE-U standards finalization, Qualcomm expressed a strong expectation that Korea, an early adopter, should be able to commercialize LTE-U soon.
However, that does not sound easy. First the Korean government must decide on how to use 5 GHz frequency, and the reasonable concerns raised by Wi-Fi advocates must be eliminated as well.
What matters most in speed/quality competition among mobile network operators is how much frequency each can obtain.
Given the circumstance, a chance of taking advantage of unlicensed band is expected to bring a new change in operators’ policies or LTE/Wi-Fi user communication environment.
Besides, country-specific 5 GHz Wi-Fi band allocations and regulations are making the circumstance even more interesting and unpredictable. Now let’s wait and see how this LTE-U issue can be handled eventually.