平流層通信HAPbasedWirelessNetwork

1、PSL IPL Ground station Switch / Gateway IP HAP 散逸層散逸層 對流層對流層 平流層平流層 中間層中間層 熱層熱層(電離層電離層) 臭氧層臭氧層 大大 氣氣 垂垂 直直 分分 層層 圖圖 大氣的垂直分層大氣的垂直分層 垂直分層垂直分層 （由下而上）（由下而上） 氣溫變化氣溫變化 特點特點 各層特點各層特點 對流層對流層 平流層平流層 中間層中間層 熱層（電離層）熱層（電離層） 散逸層散逸層 空氣十分稀薄空氣十分稀薄 氣溫隨高度 增加而升高 氣溫隨高度 增加而遞減 對流運動顯著；水汽、塵埃 集中；有復(fù)雜多變的天氣現(xiàn)象 大氣水平運動；利于高空飛行 氣溫隨

2、高度 增加而遞減 氣溫隨高度 增加急劇升高 大部分氣體以離子態(tài)存在； 反射波長較短的無線電波 高空對流 電離層好象一面反射無線電短波的鏡子，使無線電短波在 地面和電離層之間，能夠多次反射而傳播到很遠的地方。 6/6/20217 6/6/20218 6/6/20219 6/6/202110 6/6/202111 6/6/202112 6/6/202113 6/6/202114 6/6/202115 6/6/202121 6/6/202122 SkyNet, HELIOS and HALO aerial platforms. 6/6/202123 6/6/202124 6/6/202125 6/6

3、/202126 6/6/202127 6/6/202128 6/6/202129 6/6/202130 6/6/202131 6/6/202132 6/6/202133 6/6/202134 6/6/202135 6/6/202136 6/6/202137 6/6/202138 6/6/202139 6/6/202140 Introduction(1) High Altitude Platforms(HAPs) Stratospheric Platforms(SPFs) Height 17 22Km from hot-air balloons Advantage of Satellite Co

4、mmunication System Terrestrial Wireless System 平流層通信概述 平流層平臺與地面設(shè)施通信 平流層平臺之間的通信。 平流層平臺與衛(wèi)星網(wǎng)絡(luò)通信。 應(yīng)用： 寬帶無線接入 手機通信 緊急事件或災(zāi)難事件中的應(yīng)用 軍事通信 優(yōu)勢： 延遲小 覆蓋區(qū)域大 容量大： 適用性廣 系統(tǒng)造價低，通信資費便宜 快速部署 6/6/202142 平流層飛艇的主要特點： (1)長期駐空能力； (2)大范圍定點能力； (3)地面覆蓋區(qū)域較大； (4)可根據(jù)地理條件靈活機動地構(gòu)建； (5)有效載荷 承載能力較強； (6)可重復(fù)使用。 平流層通信的頻段已選定，從平流層平臺到地球為472

5、475 GHz，從地球到平流層平臺為479482 GHz。該頻段業(yè)經(jīng)1997年 世界無線電大會(WRC-97)議定，專門用于高海拔平臺電臺通信。該頻 段屬毫米波，其波長介于微波與光波之間，具有微波和光波的特點， 通信設(shè)備結(jié)構(gòu)可以做得很小，特別是可以使用小天線，但可以獲得很 強的方向性。毫米波在傳播中受雜渡影響小，對塵埃等微粒穿透能力 強，因此有很高的傳播穩(wěn)定性。 6/6/202143 平流層通信的挑戰(zhàn) 平流層大氣特性 系統(tǒng)水平需求 資源分配和網(wǎng)絡(luò)協(xié)議 平臺穩(wěn)定 雨雪衰落 6/6/202144 平流層通信具有重要的軍事應(yīng)用前 景 由于平流層通信系統(tǒng)具有費用低、可快速部署、地面設(shè)備 少、使用靈活、

6、回收方便等特點。在戰(zhàn)場上空可迅速建 立起空中信息收集和交換通道，將戰(zhàn)地信息迅速、準確 地傳輸?shù)阶鲬?zhàn)指揮中心從而達到實時指揮作戰(zhàn)的目的 另外系統(tǒng)還可以對1 000 km 地段方圓近百萬平方 公里的地面和天空進行不問斷的監(jiān)視 其主要特點如下： 1平流層通信系統(tǒng)特別適用于有限區(qū)域、邊緣地帶以及戰(zhàn) 役和應(yīng)急情況下的臨時服務(wù) 2系統(tǒng)的造價和資費較低。 3通信平臺可以不需要發(fā)射器，通過調(diào)節(jié)自身浮力，就能 自行升空并移動到預(yù)定位置 4與蜂窩網(wǎng)相比，平流層通信可實現(xiàn)視距通信，路徑損耗 只相當于半徑為2km 的蜂窩小區(qū)的損耗 6/6/202145 平流層通信平臺 1熱氣球 2太陽能飛艇 3無人飛機 4無人航空工

7、具UAV(Unmanned Aerial Vehicle) 5系留航空器(tethered aerostat 平流層建立無線通信平臺，平臺主要由以下部分組成： 多氣囊蜂窩狀結(jié)構(gòu)、并充有氦氣的多層蒙皮飛艇； 飛艇位置保持系統(tǒng)； 通信有效載荷； 用于日間供電的綜合太陽能電池陣和夜間供電的燃料電 池。 6/6/202146 飛艇是一種有推進裝置、利用浮力原理升空、可 控制飛行的飛行器 。平流層飛艇的潛在用途 是作為近空間信息平臺，主要包括： 1信息獲取。 2通信與分發(fā) 3導(dǎo)航定位，其高精度的定位信息還可用于城市 或區(qū)域的數(shù)字化，及時地滿足城市規(guī)劃、國土 測繪、地籍管理、城鄉(xiāng)建設(shè)、環(huán)境監(jiān)測、能源 開發(fā)

8、、交通監(jiān)控、防災(zāi)減災(zāi)等多種現(xiàn)代信息化 管理的社會需求 6/6/202147 HAP 之飛艇通信 一種嶄新的無線通信方式將在新世紀之初投入運行，部 分取代衛(wèi)星通信阿，該項技術(shù)的核心，是利用漂浮于地 球上空2024 km平流層的飛艇上裝載的通信平臺，實現(xiàn) 信息的傳輸或轉(zhuǎn)發(fā)，其作用如同通信衛(wèi)星上的轉(zhuǎn)發(fā)器或 地面微波通信中繼站。 飛艇通信的成本，只有地球靜止軌道通信衛(wèi)星的110， 是光纜通信的15。有關(guān)公司估計一個飛艇通信平臺造 價為4 000萬美元，其中飛艇本身1 000萬美元，能源2 000萬美元，通信設(shè)備l 000萬美元，用戶資費每分鐘幾 美分由于飛艇漂浮在2024 km的平流層，與靜止軌道 (

9、高36 000 km)衛(wèi)星和低中軌道(70011 000 km)衛(wèi)星相 比，飛艇距地面近許多，對地面終端所需功率的要求， 自然小得多，有利于實現(xiàn)終端的便攜、手持和小型化 6/6/202148 HAP：飛艇通信 飛艇升空比衛(wèi)星發(fā)射簡單得多失敗的風險 性很小，飛艇還具有重復(fù)使用和維護非常 方便的特點，它只需要每隔幾年返回地面 補充氦氣，并可在地面修理和補充通信設(shè) 備，其壽命可達數(shù)十年 6/6/202149 需要計算很多參數(shù) 6/6/202150 Introduction(2) Easy to deploy, incremental deploy Flexibility, Reconfigurabi

10、lity Low cost of operation (comparing to Satellites) Low propagation delay High Elevation! Wide area coverage Broadcast/Multicast Mobility ! BUT, Problems with Monitoring of Station Airship manufacturing Antenna technology Introduction(4) HAPs for 3G+ system because of Easy to maintain Easy to deplo

11、y Lower path loss 4G : Satellite + HAPS = MBMS（ Multimedia Broadcast Multicast Service ） Stand alone HAPs for low population with large area. Aerial Vehicles, Key Issues and Spectrum Allocation Three types 1)Propulsion + unmanned airships(balloons, aerostats) 2)High Altitude Long Endurance Platforms

12、(HALE Platforms) Solar-powered unmanned aircraft 3)Manned aircraft(?) Key Issues Airship HOVERING GPS Diesel Motors + Solar powered Spectrum Allocation ITU allocates HAPs frequency with 48/47GHz + 600MHz shared with satellite OR for 3G, 2GHz For broadband, fixed application 18-32GHz Table 5. Archite

13、ctures and Services I-Network Design- High reliability Low power consumption Lighter payload Max 150KM footprint by ITU Min. 5 degree of elevation Recommended 15+ degree to avoid clutter Architectures and Services(2) -Network Design- Frequency Reuse Cellular architecture High Bandwidth for Broadband

14、 application Fixed Channel Allocation(FCA) Dynamic Channel Allocation(DCA) HeliNet Network CAPANINA (Communications from Aerial Platform Networks Delivering Broadband communications for all ) Architectures and Services(3) -Network Design- Backhaul links, duplicated High traffic for down link Asymmet

15、ry to uplink Multiple uplinks for backhaul station Architectures and Services(4) -Network Design- Macrocell and microcell architecture (Fig.12) Rural macrocell (Fig.13) Sectoring. (Fig.14) for system capacity Architectures and Services(5) -Network Design- Ring-shaped Cell Clustering (Fig. 15). Coaxi

16、al Rings Multi-beam, controllable antenna Simpler handoff design Cell scanning (Fig. 16) Stratospheric radio-relay Maritime ( Fig.17 ) Architectures and Services -Capacity- Bandwidth Cell size depends on Antenna Directional Antenna Interference (Fig.20) Antennas(1) Requirements 1.High frequency for

17、High bandwidth 2.High gain, directional antenna 3.Multibeam antenna with 100+ beams 4.Fig. 34 for footprint 5.Beam controllability 6.Low payload and low power 7.Reliability Antennas(2) Array of the antenna at 2.2Ghz, 21Km height Wider array with high altitude, narrower array with high frequency Mult

18、ibeam Horn(MBH) Digital Beamforming(DBF) Table X Applications and Related Projects(1) - Applications - HAPs is able to RAPID DEPLOY Olympic Game, Pop concert, Rescue management Wideband Internet access, entertainment video, audio, videoconferencing, cellular telephony, digital network Standalone HAP

19、 network Supplementary network for other terrestrial network Applications and Related Projects(2) - Applications - HAP can be combined with GSM spec easily HAP with BASE STATION inside HAP only with REPEATER inside HAP with REPEATER communicates with Reference station which is NOT GSM combatible HAP

20、 ability with GSM: Fig.45 Remote control for HAP Related Projects(1) HeliNet: High Altitude Very Long Endurance unmanned solar aerodynamic platform 1.Broadband telecommunication services 2.Remote sensing 3.Navigation/local sation Related Projects(2) 2003/ 11 CAPANINA, 6th European Unions Framework H

21、eliNet based 120Mbit/s “smart roof” antenna over TRAIN mm-wave band free space-optic Also with England Korea Japan Sweden US watchdog ships also. Australia Introduction(1) Helinet(5th Frame work Programme) Scale size of HAP and 3 pilot application 1)Broadband communication 2)Environmental monitoring

22、 3)Remote sensing CAPANINA(6th) Low cost broadband technology Efficient integrated coverage Introduction(2) 1. enable high-rate communication (120 Mbps) 2. 60Km + LOS for direct service Introduction(3) Identification of appropriate application and service and associated business model Development of

23、 a system testbed (near-term) fixed user, backhaul for WLAN. (Longer-term) advanced mobile broadband wireless access Broadband Application, Service, and Infrastructure 120Mb/s + 60Km + LOS Seamlessly integrate with other delivery platform Communication standard Application and Service Selection(2) H

24、AP : end to end path 1)In isolation from any core network, providing connectivity for private network. (having few but high value links) 2) Between core networks as point-to-point trunk connections 3) In the access network, providing many users with access to core networks (many low value links) CAP

25、ANINA of eTOM Enterprise Telecoms Operations Map Aerial Platform Configurations and Spectrum Sharing (1) Aerial Platform Configurations and Spectrum Sharing (2) Work by exploiting the directionality of the user antenna 1) Simple Platform 2) Ships at different height the wider the higher 47/48GHZ, 31

26、/28GHZ ITU allotment Optical Link Capacity Optical backhaul link 10-12millimeter-wave backhaul higher data rates using millimeter wave band( 1.25Gb/s link ) Transfer non-time-critical data Interplatform links cheaper than ground comm. -450650Km range Broadband Trials To Fixed Users From Aerial Platf

27、orm Different broadband services/applications System testbed / equipment Selection of a Broadband Wireless Access Standard HAPS : 1)seamlessly with existing communication network 2)Wide adoption among potential users Good for Specific requirement, particular operating environment IEEE 802.16SC stand

28、ard Propagation Impairment ITU assigned millimeter wave band 1)Rain attenuation 2)Scattering 3)Relatively short, uncluttered link 4)Dropper effect - design of an efficient radio interface HeliNet project Result - develop a suitable channel model including a short- term numerical model - implemented

29、as a fast infrared filter with time- variant coefficients The Radio Interface Numerical channel extension for High-speed mobile application Cutting edge technology MIMO(multiple Input multiple output) Advanced signal processing Resource and Mobility Management Good communication link under rapid mov

30、ement. - Novel resource allocation strategies User - single HAP backhaul link develop: mobility, interface solve efficient spectrum QOS 2. Benefits of HAP Communication 1. Large-area coverage 2. Flexibility to respond to traffic demand 3. Low cost 4. Incremental deployment 5. Rapid deployment 6. Pla

31、tform and payload upgrading 7. Environmentally friendly 3. Satellite-HAP-Terrestrial system The system architecture proposed in this work is shown in figure below Usage User terminals cannot communication with each other without the necessary use of HAPs forward and return links. HAP-Gateway (HGTW)

32、terrestrial terminal must exists for each HAP coverage area and guarantees communications among users belonging to different HAP coverage areas HGTW links together HAP and satellite layers HAP usage mitigates multipath effects, typical of terrestrial cellular systems, and decrease geostationary sate

33、llite propagation delays This system scenario consists of tree layers Terrestrial LayerTerrestrial Layer user terminals, control and management stations Fixed Terminal (FT) and Mobile Terminal (MT) HAP LayerHAP Layer The stratospheric platform layer hosts the set of HAPs. Since HAPs do not have OBP,

34、 they act like simple hubs. GEO LayerGEO Layer Satellite layer uses GEO regenerative satellites that are provided with On-Board Processing (OBP). On-Board Processing (OBP). It can use forward channel both towards terrestrial layer and HAP layer. IV. Advantage of the scenario and open issues Advantag

35、e Simple design and implementation An HAP layer can he seen as a terrestrial system extension. satellite does not have to manage traffic of a single terrestrial terminal user terminals can be made without great financial and design efforts because they do not have the task of interacting directly wi

36、th the satellite segment. Issue A channel assignment and resource allocation schemes will need to he developed for the HAP scenario Integration with terrestrial and/or satellite architectures will also require careful planning. Choice of an HAP and GEO layers protocol platform (MPEG, DVB, ATM, IP )

37、Design of an efficient resources allocation and traffic management algorithms. Design of traffic aggregation (integrated and differentiated) techniques Design of a centralized Call Admission Control (CAC) algorithm the previous scenario adding the OBP capabilities over the HAPs Introduction(2) Intro

38、duction(3) Optical free-space point-to-point communication links Certain application involving HAPs HAPs Location in a cloud free atmospheric altitude Enabling reliable line-of-sight links between different HAPs Meshed interconnected HAP network Optical down link to the terrestrial network would be feasible using site-deversity Test Scenario(1) Tethered Balloon Trial Autumn 2004, 400m altitude was tested Data rate was 270MBPS Transmission wave band was 808nm with 500mW mean source power Angle : 16 degree Test Scenario(2) Stratos