SK Telecom and LG U+ launched LTE service back in July 2011, offering a maximum downlink speed of 75 Mbps. Shortly after in January 2012, KT also joined them, providing the same service. In August 2011, SK Telecom and LG U+ began offering VoLTE service for the first time in the world, followed by KT’s service offered two months later. 

 

In June 2013, SK Telecom became the world’s first LTE-A service provider (carrier aggregation). Before long, LG U+ and KT joined the market in July and September, respectively. Now they all provide LTE-A service with a maximum speed of 150 Mbps. This made Korea the only country in the globe where LTE-A service is available from all of its operators. 

 

Last two years since the commercialization of LTE service in 2011 saw a significant increase in the number of LTE service subscribers. As of September 2013, Korea has 54.2 million mobile service users in total, and 47.3% of them (25.6 million) have switched to LTE service within the two years. Although Korea joined the LTE market after USA (Verizon) or Japan (NTT Docomo), the transition to LTE in Korea was way faster than in the two countries. The industry expects the number of LTE subscribers to continue to grow, exceeding 28 million, which will account for more than 50% of the total mobile service users, by the end of the year.  

 

The fast transition to LTE, i.e. from 2G or 3G to LTE, was facilitated by aggressive marketing strategies of the three operators. The Korean operators have been competing fiercely for LTE subscribers because of their high ARPU. They have competitively offered deals, discounts, promotions and various benefits to attract more LTE subscribers. Also, almost all the new phone models released recently were designed for LTE. This also accelerated the transition. In addition, Koreans, early adopters of cutting edge technologies, hate to wait for slow services, and love to try new services and phones and share their reviews with others. This tendency of Korean users has also contributed to the fast transition to LTE. 

 

Table 1-1 ARPU in Q3 2013 [KRW] 

 

 

Table 1-2 below shows the three operators’ LTE services that are currently available and scheduled in near future. Their downlink speed this year was 150 Mbps, and they plan to improve the speed up to 225 Mbps next year.

 

Table 1-2. Three Korean operators’ current and planned LTE services

Given the Korea’s well-established networks, subscriber ratios, various services developed, etc., Korea certainly is leading the global LTE/LTE-A market, and will continue to do so as the number of LTE subscribers and the amount of mobile traffic grow.

 

 

 

2. LTE Deployment Status by Operator in Korea

 

The three mobile operators in Korea are all providing LTE/LTE-A services. As of Q2 2013, there are 126 million LTE subscribers globally. Korea has 23 million LTE subscribers, accounting for 10% of the global total.

 

For the same period, Korea has the highest LTE penetration rate of 47.2%, which was more than twice as high as that of the second highest group such as Singapore, Japan and the USA. 

 

As of Q3 2012, Korea has a total of 25.6 million LTE subscribers, consisting of SK Telecom’s 12.3 million, KT’s 6.8 million and LG U+’s 6.5 million of subscribers. SK Telecom has by far the largest share of 47.9%, and KT and LG U+ are running neck and neck for the second position. 

 

Below, we will briefly demonstrate how the services offered by the three Korean operators have changed and evolved over time.

 

2.1 SK Telecom

 

As of September 2013, SK Telecom, with 27.2 million subscribers (accounting for 50.2% of the national total), is in the leading position in the Korean mobile market. 45.1% of its total users, 12.3 million, are subscribing to LTE. By mid-October, 2013, only 3.5 months after the commercialization of LTE-A, the number of LTE-A subscribers had already exceeded 1 million. 65.8% of the total SK Telecom subscribers (i.e. 17.8 million) are smartphone users. 

 

SK Telecom launched commercial LTE service on July 1, 2011 in 20 MHz (DL/UL=10MHz/10MHz) in Band 5 (850 MHz), providing a maximum downlink speed of 75 Mbps. One month later, it began HD Voice VoLTE service for the first time in the world. Later in July 2012, it commercialized Multi-Carrier (MC) service using 850 MHz (Band 5) and 1800 MHz (Band 3), again for the first time in the world. 

 

SK Telecom launched the world’s first LTE-Advanced (hereinafter referred to as “LTE-A”) service in June 2013. This LTE-A service, employing Carrier Aggregation (CA) technology that combines Band 3 and Band 5 spectrum, was launched with a Category 4 device, Samsung Galaxy S4 LTE-A. SK Telecom won 20 MHz of 1800 MHz spectrum in August 2013 auction, and has provided wideband LTE service in Seoul metropolitan areas since September. The company plans to expand to nationwide coverage by June 2014. 
 

It also plans to boost downlink speeds up to 225 Mbps by using the carrier aggregation capabilities to combine 20 MHz in Band 3 and 10 MHz in Band 5 in 2014. 

 

SK Telecom has been building its fronthaul network using HFR’s Active WDM technology since 2011. For more efficient handling of soaring LTE traffic, it began migration of its existing PTN-based backhaul network (Alcatel, Huawei) into IP/MPLS network (Alcatel, Cisco) in October 2013. 

 

Figure 2-1. LTE Network Architecture Case Study: SK Telecom

 

2.2 KT

 

KT, the second largest mobile operator in Korea, has 16.3 million mobile subscribers (accounting for 30.1% of the national total) as of September 2013. 41.8% of KT’s total users, 6.8 million, are subscribing to LTE, and 67.7% (i.e. 11.1 million) are smartphone users. 

 

KT was the last one to join the LTE market, and began the LTE service using 1800 MHz (Band 3) in January 2012. The company commercialized public LTE Femto cell later in June 2012, and became the third VoLTE service provider in Korea, following SK Telecom and LG U+, in October 2012. By combining the additional 10 MHz in 1800 MHz spectrum that it won in the August 2013 auction with its existing 10 MHz, KT could secure 20 MHz of DL wideband, allowing the company to offer wideband LTE service from September. At the same time, with the commercialization of 900 MHz (Band 8), KT also launched the LTE-A service by using CA that combines Band 3 and Band 8, for the third time in Korea AND in the world. In November 2013, it began the commercialized Wideband LTE home femtocell service for the first time in the world. 

 

KT upgraded the quality of its Olleh TV Mobile service to the HD quality and 4 Mbps version in June 2013 for the first time in Korea. With this upgrade, competition among the three operators to provide mobile IPTV services with the best video quality has become even fiercer than ever. KT introduced Always Best Connected (ABC) solution (from Airplug) that ensures seamless streaming of a video in the HD quality with less data consumption.  

 

2.3 LG U+

 

LG U+, the third largest mobile operator in Korea, has 10.7 million mobile subscribers (accounting for 19.7% of the national total) as of September 2013.

 

The company began its LTE service using 850 MHz (Band 5) in July 2011, and then a year later in July 2012, it launched Multi-carrier (MC) service using 2100 MHz (Band 1). LG U+, with no 3G network, completed construction of a nationwide LTE network for the first time in the world in April 2012. Then in July 2013, it launched LTE-A service for the second time in the world by using the CA technique that allows combining of Band 1 and Band 5 carriers. With the additional 20 MHz (DL) in 2600 MHz (Band 7) that it won in the August 2013 auction, it is currently working on construction of a new network. 

 

In August 2012, LG U+ and SK Telecom, launched the world’s first VoLTE service, HD Voice over LTE network exclusively. In July 2013, Multi-view service (U+ HDTV) that allows users to watch four live channels all at the same time in one screen was introduced, again for the first time in the world.

As of September 2013, LG U+ has the highest penetration rate, with 61.1% of its mobile service users (i.e. 6.5 million) subscribing to LTE service, followed by SK Telecom at 45.1%, KT at 41.8%, Verizon (in the USA) at 37.8%, and NTT Docomo (in Japan) at 26.5%. Also, the company’s smartphone penetration rate is 71.4%, highest among the three, and the rate accounts for 7.7 million users.  

 

 

3. LTE Frequency Commercialization Status in Korea

 

In August 2013, there was a frequency auction in 1800 MHz and 2600 MHz bands. So, we will look into how LTE frequencies have been commercialized in Korea in the following four phases: i) before the August 2013 auction, ii) the results of the auction, iii) the commercialization status of acquired LTE frequencies as of November 2013, and iv) plans for further commercialization in 2014.

 

3.1 Prior to the August 2013 auction

 

Table 3-1 shows LTE frequency bands allocated to the three mobile operators in Korea before the auction. 

 

Table 3-1. LTE Frequency bands used in commercial networks in Korea (before Aug. 30, 2013)

 

SK Telecom and LG U+ launched LTE-A service by using CA that allows combining of two carriers into one 20 MHz carrier in June and July, respectively. At that time, KT had not provided the service yet. And that mainly caused the decline in its subscribers this year. 

 

Table 3-2. LTE-A (Carrier aggregation) services in Korea (as of Aug. 2013)

CA is applied only to downlink direction and Cat 4 devices. A Cat. 4 device using CA can receive data at a maximum speed of 150 Mbps.

 

 

Figure 3-1. LTE frequency bands used in commercial networks before the frequency auction in 2013 

 

3.2 The Result of the LTE Frequency Auction on August 30, 2013

 

On August 30, 2013, the Ministry of Science, ICT and Future Planning announced the results of the LTE frequency auction for 1800 MHz (Band 3) and 2600 MHz (Band 7) as shown in Table 2 below. As a result of the auction, SK Telecom won additional 35 MHz (DL/UL = 20/15 MHz) in 1800 MHz band, KT acquired additional 15 MHz (DL/UL = 10/5 MHz) in 1800 MHz band, and LG U+ won additional 40 MHz (DL/UL = 20/20 MHz) in 2600 MHz band. Through this auction, all of them were able to secure their own Wideband LTE bands.

 

Table 3-3. Allocated frequencies after the auction on Aug. 30, 2013

 

KT benefits most from the auction. KT can utilize its existent nationwide network in 1800 MHz band. Therefore, KT is able to provide nationwide Wideband LTE service with minimum Capex. 
For fair competition among the operators, the Korean government has imposed certain restrictions on KT.  It, therefore, was not allowed to launch its nationwide Wideband LTE service before July 2014. 

 

Figure 3-2 shows the LTE frequencies allocated to the three operators before AND after the August 2013 auction.

 

Figure 3-2. The results of the LTE frequency auction on August 30, 2013 

 

3.3 After the August 2013 Auction (as of November 2013)

 

Figure 3-3 shows the LTE spectrum allocation spread in Korea reflecting the results of the latest spectrum auction.

Combining newly acquired 1800 MHz spectrum with its existing 1800 MHz holdings, KT now has 20 MHz of continuous DL spectrum. The company launched the commercial Wideband LTE service using the DL 20 MHz in 1800 MHz in Seoul metropolitan areas on September 14, 2013, for the first time in Korea.

Also, in November, it completed construction of a wideband LTE network for Seoul metropolitan areas. 

For regions excluding Seoul metropolitan areas, the company launched LTE-A service at a maximum speed of 150 Mbps by combining its two 10MHz (900MHz and 1.8GHz spectrum bands) holdings on September 14, 2013. KT was the last among the three to launch the LTE-A service. 

 

SK Telecom began offering the commercial Wideband LTE service using the newly acquired DL 20MHz in 1800MHz spectrum in Seoul metropolitan areas on September 30, 2013 , and plans to build a Wideband LTE network in Seoul metropolitan area by the end of November. 

LG U+ has already started building a new 2600 MHz network, and said it plans to start the Wideband LTE service using DL 20MHz in 2600MHz band in Seoul metropolitan areas in December 2013 .

 

 

Table 3-4. LTE-A (Carrier Aggregation) services in Korea (2013. 11)

 

Table 3-5. Wideband LTE services in Korea (2013. 11)

 

With the launch of the Wideband LTE service in Seoul metropolitan areas, the existing customers with LTE phones (Cat. 3 device) without CA can enjoy 100 Mbps maximum speed without changing phones, and the customers with LTE-A phones (Cat. 4 device) can enjoy 150 Mbps maximum speed even without using CA. 

 

Figure 3-3. LTE frequency bands used in commercial networks after the frequency auction in 2013

 

3.4 Plans for Further Commercialization of LTE Frequency in 2014

 

All three Korean mobile operators plan to build nationwide networks operating with Wideband LTE carriers.

 

KT has already completed its nationwide LTE network in 1800 MHz band. So, it can begin its Wideband LTE service nationwide right away once restrictions imposed upon spectrum auction are released in July 2014.

SK Telecom has completed construction of a nationwide network in 850 MHz band. However, what it acquired in the auction was Wideband LTE frequency in 1800 MHz band. Therefore, unlike KT, additional Capex is needed to build a nationwide network in the band. SK Telecom also plans to open a nationwide wideband LTE network in July 2014.

LG U+ is also planning to build a nationwide network in 2.6 GHz and launch Wideband LTE service in July 2014.

 

In 2014, all three operators will launch CA by combining their Wideband LTE band (20 MHz) and existing 10MHz band.

 

They all announced their plan to provide 225 Mbps downlink speeds by employing Wideband LTE carrier-involved CA in 2014. Using this CA, SK Telecom and KT can combine up to 30 MHz while LG U+ can combine up to 30 or 40 MHz. Then, users can enjoy max downlink speeds of 225 Mbps when using 30 MHz bandwidth, and 300 Mbps when using 40 MHz bandwidth. 

 

The CA technique cannot be employed in Cat. 4 devices that support only up to 150 Mbps. So, Cat. 6 devices that support up to 300 Mbps are to be released in 2014.

 

LG U+ can combine bandwidths up to 40 MHz, and thus it plans to support 300 Mbps using 3-band CA in 2015.

 

Table 3-6. Planned LTE services in 2014

 

Figure 3-4. Building nationwide networks in Wideband LTE bands (H2 2014)

 

 

4. LTE Services: Mobile Broadband, Mobile IPTV and VoLTE

 

4.1 Mobile Broadband

 

As of November 2013, mobile Internet access services currently provided or scheduled to be provided by the three operators are as seen in Table 4-1. The three are providing their LTE/LTE-A service users with maximum downlink speeds of 150 Mbps, which is higher than wired FTTH service’s 100 Mbps. Next year, they all plan to increase the speed to 225 Mbps, using CA that combines a 20 MHz wideband carrier and a 10 MHz carrier. 

 

Table 4-1. Three Korean operators’ current and planned LTE services

 

4.2 Mobile IPTV

 

The three operators have been putting a lot of effort into promoting LTE-A. They all upgraded the quality of their mobile IPTV and UX, with commercialization of LTE-A service in June 2013. KT began HD streaming with 4 Mbps in June 2013. One month later, SK Telecom began its Full HD-level mobile streaming with 4 Mbps and 1080P for mobile devices for the first time in the world. In the meantime, LG U+, first time in the world, introduced Multi-view service (U+ HDTV) that allows users to watch four live channels at the same time in July 2013.

Mobile users can subscribe to any mobile IPTV service, and use the video service there, at no cost or with fixed monthly payments, regardless of their network operator (All the mobile IPTV services available from the three operators are OTT type, not walled-garden type).

 

They all offer video services like Live TV and VoD services, using the same streaming protocol and codec, i.e. HLS and H.264. In addition, they all utilize Adaptive Streaming that automatically adjusts content streaming rates and bit rates depending on the conditions of the network that users are using, and ensures uninterrupted streaming of a video on mobile TVs. 

 

Mobile IPTV services currently offered by the three operators are analyzed in Table 4-2 below. 

 

Table 4-2. Characteristics of mobile IPTV services in Korea

 

4.3 VoLTE

 

Today, VoLTE services are available from only four operators in the world: SK Telecom, LG U+, KT (all from Korea) and Evolve Broadband (from the USA) [“Evolution to LTE Report”, GSA, October 17, 2013]. The Korean operators all launched the VoLTE service in 2012. SK Telecom and LG U+ began the world’s first VoLTE services called “HD Voice” and “Jieum”, respectively, in August 2012. Two months later, KT also offered the same service named “HD Voice”.

 

In 2013, SK Telecom launched another service named “Single Radio Voice Call Continuity (SRVCC)”, complementing the VoLTE service. SRVCC supports seamless handovers between 3G and LTE networks, and thus can achieve uninterrupted voice services even in a congested network. LG U+ supports the VoLTE service using its LTE network only. 

 

In order for an operator to provide VoLTE services, an IMS network is required, and its LTE core network and radio access network should be able to provide the VoLTE service with QoS differentiated from other data (e.g. establishment of dedicated EPS bearers). Table 4-3 lists the characteristics of VoLTE services provided by the three operators.

 

Table 4-3. Characteristics of VoLTE services in Korea

 

5. LTE Equipments