On May 20, Chairman Chang-gyu Hwang of KT (with sales of KRW 23.8 trillion in 2013) announced that "KT will open up a new age of GiGAtopia by investing KRW 4.5 trillion (USD 4.4 billion) in GiGA FTTH, GiGA Path (heterogeneous networks convergence technology that combines LTE and Wi-Fi networks), and GiGA Wire (copper wire-based transmission technology) for the next three years." Later on Ju...

In the past two years, some new technologies have been introduced in Korea, apparently increasing broadband Internet speeds 3~5 times faster, from 100 Mbps to 300~500 Mbps, instantly. It certainly is fascinating in that such speed improvement was achieved without the hassle of re-cabling construction in apartment buildings. Because 100 Mbps had seemed unbeatable for almost a decade, this sure w...

In the CoMP scenarios defined in 3GPP Release 111 and Release 122, CoMP is used within a single eNB (intra-eNB) with ideal backhaul only - in restricted areas in Release 11 among eNBs (inter-eNB) with non-ideal backhaul as well - in more expanded areas in Release 12 According to NGMN3, ideal backhaul refers to one with latency of 2.5 usecs or less and capacity of 10 Gbps or higher, whe...

Today, we will learn about CoMP, an inter-cell cooperation technology in LTE-A, since we learned about ICIC and eICIC in the previous posts. At an early stage of LTE/LTE-A, offering high speed is the most important marketing point for operators. However, as LTE subscribers and traffic grow, satisfying users with high Quality of Experience (QoE), for example, by improving user throughputs at cel...

Enhanced Inter-Cell Interference Coordination (eICIC) As noted in the previous post about ICIC, we will find out about enhanced Inter-Cell Interference Coordination (eICIC), an interference control technology in LTE-A in this post. In LTE/LTE-A, one key challenge for operators is that they have to increase network capacity to keep up with fast-growing traffic. Especially, crowded areas in m...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

In this post, we will talk about “jitter” introduced in the fronthaul network of LTE C-RAN. As shown in the figure on the right, jitter refers to the skew or variation in time or phase of a digital signal exchanged between communication systems. This jitter can eventually cause errors during the data and clock recovery process at RRH. Then, why should we be worried about jitter...

KT’s Vision: GiGAtopia Source: KT What? Chairman Chang-gyu Hwang of KT (with sales of KRW 23.8 trillion in 2013), at a press conference held at KT Olleh Square in Gwanghwamun, Seoul on May 20, announced that "KT will open up a new age of GiGAtopia by investing KRW 4.5 trillion (USD 4.4 billion) in GiGA FTTH, GiGA Path (heterogeneous networks convergence technology that combines...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

As mobile communication technology has evolved dramatically, from LTE (10 MHz) to LTE-A (10+10 MHz), and then to wideband LTE (20 MHz), South Korea's mobile market is hotter than ever with its big 3 operators competing fiercely in speed and quality (see Netmanias Report, LTE in Korea UPDATE - May 1, 2014). Operators can offer different maximum speeds depending on how wide frequency bandwidt...

HFR is probably most known as a vendor of wired/wireless network equipment like Mobile fronthaul, Carrier Ethernet, FTTx, etc. Today, we are going to hear from Dr. J.H. Lee (jongheonlee@hfrnet.com), CTO of HFR about one of its most popular solutions, flexiHaulTM, a mobile optical access solution. 1. Welcome! Thank you for being with us. Can you tell us a little bit about HFR first?...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

Switching and Routing 1. Switching and Routing for Dummies - Ethernet Switching 2. Switching and Routing for Dummies - IP Routing 3. Switching and Routing - Part 1. Router Architecture 4. Switching and Routing - Part 2. Packet Forwarding by IP Router 5. Switching and Routing - Part 3. L2 (Ethernet) Switching by L3 Switch 6. Switching...

1. Traditional RAN Architecture and Issues 1.1 Issue No. 1: Degraded service quality and network performance due to inter-cell interference 1.2 Issue No. 2: Increased costs of building and operating cell sites 2. Degradation of service quality and network performance due to inter-cell interference: Prevented by reducing X2 distance 3. Costs of building and operating cell sites: Reduced...

In C-RAN (Centralized/Cloud RAN), the more RRHs are covered by one CO (BBU hostelling site), i) the fewer COs are required, and ii) the more BBUs can be centralized at one CO. This allows for the most efficient utilization of BBU resources, thereby significantly reducing CAPEX/OPEX. For this reason, the maximum separation distance between RRH and BBU should be secured. This distance is cons...

Our question in this post is: Why does the CPRI link between BBU (at CO) and RRH (at Cell Site) in C-RAN require a ultra high Gbps bandwidth? Before you read this post, we advise you to read our previous post, "CPRI (1): Emergence of C-RAN and CPRI overview". The CPRI link capacities required between BBU and RRH in the C-RAN architecture are as follows: Table 1. CPRI data rates...

Emergence of C-RAN (Separation of Baseband and Radio, and Baseband Centralization) Today, global LTE operators are competing with one another more fiercely than ever, under the pressure to provide better service quality and higher speed. Conventional Internet traffic has been increasing steadily. What's more, mobile traffic resulting from OTT video services, such as YouTube, Mobile IPT...

Google Global Caches (GGCs) have already been deployed in many telecom operators' data centers around the world, caching YouTube video files like Psy's Gangnam Style for the local users. This allows people around the globe to watch Psy singing and dancing without buffering through their local GGCs. Korean operators like SK Telecom, LG U+ and KINX have also made the same move in February...