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教育部補助「 行動寬頻尖端技術跨校教學 聯盟 第三期 計畫 - 行動寬頻網路與應用 - 小細胞基站聯盟 中心」 Cloud RAN: 雲端 無線接取網路與 應用 課程單元 : 行動寬頻網路之演進與 Small Cell 架構 (Draft). 計畫主持人:許蒼嶺 授課 教師 :萬欽德. 課程單元目標. 了解行動通訊發展之基本驅動因素 了解各世代行動通訊技術與發展 了解 LTE-A/4G 行動通訊的 發展現況 了解 B4G/5G 行動通訊 的技術需求 了解 Small Cell 小 細胞 基地台系統之基礎. 課程單元大綱. 行動通訊之 演進
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教育部補助「行動寬頻尖端技術跨校教學聯盟第三期計畫-行動寬頻網路與應用-小細胞基站聯盟中心」CloudRAN: 雲端無線接取網路與應用課程單元:行動寬頻網路之演進與 Small Cell 架構(Draft) 計畫主持人:許蒼嶺 授課教師:萬欽德
課程單元目標 • 了解行動通訊發展之基本驅動因素 • 了解各世代行動通訊技術與發展 • 了解 LTE-A/4G 行動通訊的發展現況 • 了解 B4G/5G 行動通訊的技術需求 • 了解 Small Cell 小細胞基地台系統之基礎
課程單元大綱 • 行動通訊之演進 • 行動寬頻網路 • LTE-A/4G • B4G/5G • 小細胞基站 Small Cell 架構
Reference: NTT DoCoMo Mobile Communications Networks for Multimedia Services
Communications and Networks • Communication Systems • Public Switched Telephone Network (PSTN)(公用交換電話網路) • Cellular Phonesand Networks(行動電話通訊網路) • Computer networks (LANs, WANs, and the Internet)(計算機網路) • WPANs (Bluetooth, Zigbee and UWB)(無線個人網路) • Radio and TV broadcasting(廣播與電視) • Satellite Systems (衛星系統) • Information Contents • Voice, audio, data, video, music, email, web pages, etc.
Wireless Communications and Networks:Service Integration Internet-based Communications (store-and- forward) Telephone-based Communications (real-time) Broadcasting Speech Recognition Collaboration Email Voice Mail Messaging Video-Conferencing New-Generation Communications Services Wireless Mobility
第一代 (1G , First Generation) • 蜂巢式行動通訊系統達成射頻通道之再使用 (frequency reuse) • 早期的類比通訊系統 • 美國:AMPS(Advanced Mobile Phone System) • 英國:Total Access Communication System(TACS) • 北歐:Nordic Mobile Telephone(NMT) • 採用類比式FM調變方式 • 採用FDMA(Frequency Division Multiple Access)多重存取方式 • 以語音通訊為主,無法支援數據通訊服務
第二代 (2G , Second Generation) • 2G主要分為 GSM (Global System for Mobile Communications) 與 IS-95 (Interim Standard 95) • GSM 行動通訊系統特點: (1) 全數位式 (4) 客戶識別 (SIM) (2) 細胞式 (cellular) (5) 保密通訊 (3) TDMA / FDMA (6) 國際漫遊 (roaming)
第二代 (2G , Second Generation)(Cont.) • MSC : Mobile-service Switching Center • BSC : Base Station Controller • AUC : Authentication Center • BTS : Base Transceiver Station • HLR : Home Location Register • VLR : Visitor Location Register • EIR : Equipment Identity Register • PSTN: Public Switching Telephone Network • SGSN:Serving GPRS Support Node • GGSN:Gateway GPRS Support Node
第二代 (2G , Second Generation)(Cont.) • 2.5G,GPRS(General Packet Radio Service): • HSCSD (High Speed Circuit-Switched Data):採用電路交換,加強GSM並將資料速率增加至115Kbps,使用TDMA存取技術 • GPRS (General Packet Radio Service) :採用封包交換,加強GSM並將資料速率增加至168Kbps,使用TDMA存取技術 • EDGE (Enhanced Data Rates for Global Evolution):資料速率為384Kbps • GPRS 為手機提供新的數據加值服務(new non-voice value added service) 。如 FTP (File Transfer Protocol), email, telnet, web browsing, chat等。
第二代 (2G , Second Generation)(Cont.) • GPRS 採分封交換(packet switching),以多時槽(time slot)傳送封包,較經濟有效。數據率可為 14.4 kbps (1 time slot) 到115.2 kbps (8 time slots) 。 • 因GPRS 與 GSM 共用實體通道,故實務上 8 個全分配給 GPRS 之機率不高。以 3 個time slot分配給 GPRS 估算,數據率為 43.2 kbps。 • GSM 之數據率為9.6 kbps,而短訊 (Short Message Service) 長160 characters。 • 手機可經由 GSM + GPRS 連上 Internet 或 Intranet。 • GPRS 為手機提供遠端存取與控制智慧型家電。
Cellular Scenario (Backbone Networks) • Better QoS, scheduling • Better Mobility within the cellular network • Integrated voice/data Authentication • Downside is excessive edge network delays, costs of network deployment.
第三代 (3G , Third Generation) • WCDMA (Wideband Code Division Multiple Access):標準頻寬為5MHz。UTRAN系統就是使用WCDMA,其以GSM MAP網路為基礎。 • 進階的TDMA (Advanced Time division multiple access) :UWC-136被採用,則也僅限北美地區使用 • 混合式的CDMA/TDMA (Hybrid CDMA/TDMA):與UTRAN的TDD模式相同 • OFDM (Orthogonal frequency-division multiplexing):因為功率上的問題,而未成為IMT-2000選擇的規格所採用之技術 • IMT-2000 (International Mobile Telecommunications-2000):為所有3G系統的總括規格
Growing Mobile Data Traffic • Mobile data traffic is growing exponentially, caused by mobile internet offerings and improved user experience with new device types. • LTEperspective • Long term evolution perspective for 2G and 3G networks based on WCDMA/HSDPA, GSM/EDGE, TD-SCDMA, and CDMA2000 technologies.
Consideration for LTE • Definition began: Nov. 2004 • 3GPP (3rd Generation Partnership Project) began a project to define the Long-Term Evolution (LTE) for Universal Mobile Telecommunications System (UMTS) cellular technology • Considerations: • Higher performance • Backwards compatible • Wide applications
Requirements and Expectations for LTE • Only Packet Switched Services • Data Rate • Latency • Bandwidth • Interworking • Multimedia Broadcast Multicast Services (MBMS) • Duplex modes • Quality of Service • Modulation Technologies
Long Term Evolution (LTE) • LTE starts from 3GPP release 8 (Nov. 2008) • LTE Advanced (LTE-A) starts from 3GPP release 10 (March 2011) • LTE minimizes the number of network elements • Optimized for Packet Switched (PS) services • Can handle Circuit Switched (CS) services • Support speech service using Voice over IP • Support Multimedia Broadcast Multicast Services (MBMS) for the transmission of mobile TV
LTE World Map • 537 commercial networks in 170 countries (Nov., 2016) • Forecast 560+ operators by the end of 2016. • 80 commercial LTE TDD networks are launched • 254 (47%) commercial LTE networks have deployed LTE 1800 Source: GSA –Evolution to LTE report Nov., 2016
LTE Deployments Status • GSA forecasts 560 commercial LTE networks in 170 countries by end of 2016 Source: GSA –Evolution to LTE report Oct., 2016
Spectrum for LTE Deployments • LTE can be deployed in existing 2G or 3G bands, and in new spectrum such as 2.6 GHz and the Digital Dividend bands (700 or 800 MHz depending on the region). • LTE deployments are typically in 700 MHz and existing AWS (1.7/2.1 GHz) spectrum in the USA. • Commercial LTE800 services have been launched initially targeting rural broadband needs. The main capacity band in most regions is 2.6 GHz. • There is high interest in using re-farmed 2G spectrum for LTE, especially 1800 MHz, and in a few cases 900 MHz, as most regulators now adopt a technology-neutral approach. • Initial LTE FDD deployments in Japan use 800/850 MHz, 1.5 GHz, 1.7 GHz and 2.1 GHz (operator-dependant).
LTE Prime Spectrum Bands • 2.6 GHz is new spectrum and the main LTE capacity. • Digital Dividend is new spectrum for coverage • Initial network launches are mainly LTE-FDD. • The most common frequencies used for LTE: –700 MHz: band 13, band 17 –800 MHz: band 20 –1800 MHz: band 3 –2600 MHz: band 7 Source: 3GPP TS 36.104 V 10.6.0 (2012-03)
LTE User Devices Source: GSA GAMBoD-LTE, July, 2013
Conditions Affecting Mobile Communications
Why Small Cell? • Coverage • Voice Quality • VoLTE • EVS codec • Throughput
Small Cell • As more subscribers use mobile broadband services from their smartphones and tablets, the demand for bandwidth and coverage is increasing. • MSPs (Mobile Service Providers) are updating their networks to LTE networks and adding small cells as part of a heterogeneous network (HetNet) architecture. • Small cells are wireless infrastructure equipment that operates in licensed bands within cellular networks.
Pros • Because of their size and low power requirements, small cells are simpler and can be deployed more quickly than macro cells. • As mobile network operators (MNOs) build out LTE networks, the need for additional coverage and capacity in specific locations is driving them to deploy small cell networks. • Cheaper • Doesn’t require special phones • High quality • Open or restricted access
Cons • Significantly increase the signaling load on the core network • Hard to management and scheduling • More Interference • Security
Use Cases • There are three types of small cells with varying capacity, coverage, power requirements. • A metrocell provide increased capacity in urban hotspots or coverage in a rural location.
Circuit Switched Core • The Radio Network Controller (or RNC)is a governing element in the UMTS radio access network and is responsible for controlling the NodeBs that are connected to it. • Mobile switching center (MSC):This is essentially the same as that within GSM, and it manages the circuit switched calls under way. • Gateway MSC (GMSC):GMSC has all the standard functionality of a MSC (Mobile Switching Centre) but provides interconnectivity between other licensed operators. • PSTN (public switched telephone network): It is the world's collection of interconnected voice-oriented public telephone networks.
Packet Switched Core • Serving GPRS Support Node (SGSN):The SGSN provides a number of functions within the UMTS network architecture. • Mobility management: When a UE attaches to the Packet Switched domain of the UMTS Core Network, the SGSN generates MM information based on the mobile's current location. • Session management: The SGSN manages the data sessions providing the required quality of service and also managing what are termed the PDP (Packet data Protocol) contexts, i.e. the pipes over which the data is sent. • Interaction with other areas of the network: The SGSN is able to manage its elements within the network only by communicating with other areas of the network, e.g. MSC and other circuit switched areas. • Billing: The SGSN is also responsible billing. It achieves this by monitoring the flow of user data across the GPRS network. CDRs (Call Detail Records) are generated by the SGSN before being transferred to the charging entities (Charging Gateway Function, CGF).