High Altitude Platform based
Wireless Network
Summer 2009
ICT
TUWien
Ha Yoon Song, Guestprofessor
song@ict.tuwien.ac.at
PSL
IPL
HAP
Ground station
Switch /
Gateway
IP
Broadband Communications via High
Altitude Platforms(HAPs) – A survey
S. Karapantazis and F.-N. Pavlidou
Introduction(1)
High Altitude Platforms(HAPs)
Stratospheric Platforms(SPFs)
Height 17 ~ 22Km
from hot-air balloons
Advantage of
Satellite Communication System
Terrestrial Wireless System
Introduction(2)
•
Easy to deploy, incremental deploy
• Flexibility, Reconfigurability
• 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 deploy
• Lower path loss
•
4G : Satellite + HAPS = MBMS.
•
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(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.
Architectures and Services I-Network DesignHigh 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 DesignFrequency Reuse
Cellular architecture
High Bandwidth for Broadband application
Fixed Channel Allocation(FCA)
Dynamic Channel Allocation(DCA)
HeliNet Network
CAPANINA
Architectures and Services(3) -Network Design-
Backhaul links, duplicated
High traffic for down link
Asymmetry 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).
Coaxial 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)
Channel Modeling and Transmission Techniques
( Transmission and Coding 1 )
HeliNet : QP,, QAM, M-PSK(starQAM), CPM,
GMSK, MA-MSK)
Table 11
Elevation!
Antennas(1)
Requirements
1.
2.
3.
4.
5.
6.
7.
High frequency for High bandwidth
High gain, directional antenna
Multibeam antenna with 100+ beams
Fig. 34 for footprint
Beam controllability
Low payload and low power
Reliability
Antennas(2)
Array of the antenna at 2.2Ghz, 21Km height
Wider array with high altitude, narrower array
with high frequency
Multibeam Horn(MBH)
Digital Beamforming(DBF)
Table XⅡ
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 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 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 Union’s Framework
HeliNet 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
INTEGRATING USERS
INTO THE WIDER BROADBAND
NETWORK VIA
HIGH ALTITUDE PLATFORM
PEM
Introduction(1)
Helinet(5th Frame work Programme)
 Scale size of HAP and 3 pilot application
1)Broadband communication
2)Environmental monitoring
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 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(1)
QOS parameter : delay, delay variation, packet loss
Application and Service Selection(2)
•
HAP : 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)
• CAPANINA 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, 31/28GHZ 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.
-450~650Km range
Broadband Trials To Fixed Users From Aerial Platform
•Different broadband services/applications
•System testbed / equipment
System Testbed(1)
•
3 different aerial platform technologies
1)Tethered platform
2)Stratospheric balloon
3)Full HAP
• Trial 1
1)BFWA up to fixed user using 28GHZband
2)end-to-end connectivity
3)High speed internet and video
4)Optical communication
System Testbed(2)
Trial 2
 Balloon
 -> 28/29 GHZ
 Optical communication
 High data rate backhaul link
 Integration of multipayload system
Trial 3 2006
Wireless Equipment
Millimeter-wave trial equipment is based
around 28/29 GHz and 28/31GHz frequency
Trial1 : tethered aerostat
- optical fiber, power
Trial2 : free flying stratospheric balloon
- Strict weight
- single beam coverage of footprint
- millimeter wave link
Free-Space Optical
Communications Equipment
Optical beam for optical interplatform link
dependent
Atmosphere effect?
Intensity modulation with direct detection –
short implementation time
Ground station tracking system
-> trial 1 : 270Mbps video signal
Delivery Broadband to
High-Speed Vehicles
•
•
CAPANINA project for High Speed Vehicles
Delivering broadband (backhaul) to trains
equipped with onboard WLAN access point
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 – standard
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 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 movement.
-> Novel resource allocation strategies
 User - single HAP backhaul link develop: mobility,
interface solve
 efficient spectrum
 QOS
An intergrated Satellite_HAP-Terrestrial
system architecture: resources allocation
and traffic management issues
P. Pace, G. Aloi, F. De Rango, E. Natalizio, A.
Molinaro, S. Marano
Dept. DEIS - University of Calabria
Arcavacata di Rende (Cosenza) - Italy
{ppace, aloi, derango, enatalizio, molinaro,
marano) @deis.unical.it
contents
1. Introduction
2. Benefits of HAP Communication
3. Satellite-HAP-Terrestrial system
4. Advantage of the scenario and open issues
4. Conclusion
1. Introduction
Terminology

HMCS(HAP Master Control Station)


The terrestrial layer’s terminals within the same HAP coverage
area have to use HAP transponder and HAP Master Control
Station (HMCS) to send and receive data amongst themselves.
HGTW(HAP Gateway Station)

the HAP Gateway stations (HGTW) guarantees communications
among users belonging to different HAP coverage areas using the
CEO satellite links.
In order to guarantee an adequate quality of service to these
kinds of service, it is required an efficient resources allocation
and traffic management algorithm to be implemented inside
the HMCS and HGTW stations.
Next generation satellite systems will provide personal communications to
mobile and fixed users. As the demand grows for communication services,
wireless solutions are becoming increasingly important.  HAP
Platform : airplanes or airships , manned or unmanned
Position 
“wind”
HAPs can offer a wide range of services. Such services may particularly
valuable where existing ground infrastructure is missing or difficult.
HAPs are ideally suited to the provision of centralized adaptable
resources allocation, i.e. flexible and responsive frequency reuse patterns
and cell sizes, unconstrained by the physical location of base-stations, the
smaller cells provide greater overall capacity as frequencies are reused a
greater number of times within a given geographical area as shown in
figure 2.
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. Platform 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) 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 satellite propagation delays
This system scenario consists of tree layers
Terrestrial Layer

user terminals, control and management stations
 Fixed Terminal (FT) and Mobile Terminal (MT)
HAP Layer

The stratospheric platform layer hosts the set of HAPs. Since HAPs do not
have OBP, they act like simple hubs.
GEO Layer

Satellite layer uses GEO regenerative satellites that are provided with OnBoard Processing (OBP). It can use forward channel both towards
terrestrial layer and HAP layer.
IV. Advantage of the scenario and open issues
Advantage

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 with 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
…)

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
should be possible to share tasks at different layers and use less complex
ground control station (HMCS, Satellite-MCS).
the users terminals should be hybrid terminals, able to work on different
frequency bands and with very different power levels
these terminals will be more complex and expensive
laser communications

can transmit data at rates up to 450 Mbps.

SILEX terminal could be used for a satellite HAPS link for
high data rate communications.
V. Conclusion
This paper investigated the design of a integrated satellite-HAP-terrestrial
architecture for telecommunications.
The haps layer give a added value to wireless communications because it
offers reduced propagation delay and offer a broadband covertures.
802.16e vs 802.20
Wi-Fi Wi-MAX, MBWA, 3G
2008.7.21
PEM
802.16 vs. 802.20 (1)
•IEEE,
2 working groups
•Spec. for new mobile air interface for
wireless broadband
•Similar, but
•802.16
e : mobility in the 2 to 6 GHz
•802.20 : operation in licensed below
3.5GHz
802.16 vs. 802.20 (2)
•802.16e
from 802.16a(WiMAX Forum)
standard
•802.16
uses existing Broadband Wireless
Access(BWA)
•
“inherent mobility of wireless media”
•Fills
gap between Wireless MAN and WLAN
802.16 vs. 802.20 (3)
•802.20
•Wireless
MAN, real time data
transmission rate
•15Km cell range
•Upto 250Km/h velocity
•
cf)802.16 for (120-150Km/h)
802.16 vs. 802.20 (4)
•802.16e
is looking at the mobile user walking
around with PDA or laptop.
•802.20 will address high-speed mobility
issue.
•Deployment in different method
•1)16e : 16a cell footprint
•2)20 : wider footprint deploy
802.16 vs. 802.20 (5)
•
•
802.20 will be a compete to 3G
“if 802.16e drives demand initially and
people are getting thirsty for it, a .20 solution
could be deployed on a widespread basis
and take advantage of users wants and
demand for high-speed data.”
Bringing Wireless Access to the Automobile
Wireless Fidelity(Wi-Fi) : 802.11p
-air interface between a wireless client and a base station
Worldwide interoperability of Microwave Access(WiMAX) : 802.16
- metropolitan area에서 last mile problem 등 connection에 대한 접근
Mobile Broadband Wireless Access(MBWA) : 802.20
- To enable worldwide deployment of affordable ubiquitous, interoperable
multi-vender mobile BWA
Third-Generation (3G)
- Wireless network access for both stationary and moving
Comparison Parameters
•
Performance
-
Application dependent on (latency, low/high band)
•
Coverage Area
Distance between Base station
Reliability
Average number of dropped packet
Security
encryption, authentication
Mobility
Speed of mobile access point
•
•
•
-
Wi-Fi(802.11p)
•
Mostly for mobility
• First high-speed wireless
• Limited range
1)300 feet (for 802.11a)
2)1000feet (for 802.11p)
WiMAX(802.16e)
•Standard
for point-to-multi point wireless network
•“last mile” connectivity
•DSL like data rate
•30 miles
MBWA (802.20)
•Mobile
broadband, high-speed
•155 mile/hour, for train
•Wireless MAN, real-time transmission
•Required channel bandwidth is small
•9 mile of BS range
•Handoff solution between 802.20 and 802.11-based LAN
3G
High-speed wireless communication
Cellular technology
Voice, data transmission for long-range wireless access
Performance
Coverage, mobility comparison
Reliability, Security Comparison
Conclusion
•
Performance-latency, bandwidth
- WiMAX is the best. (100Mbps, 25-40ms)
• Coverage area
- MBWA is the broadest
• Reliability (???)
•
Security (encryption, authentication)
- Wi-Fi, 3G
• Mobility (speed)
- MBWA
Optical Free-Space Communications
Downlinks from Stratospheric Platforms
Introduction(1)
STROPEX

STRatospheric Optical Downlink Experiment
The CAPANINA Project



Development of low-cost broadband service
Providing efficient ubiquitous coverage
Both mm-wave band and free space optic communication technology will
be used.
Free space optic communication



Deliver very high data rates in clear air conditions
Used for Interplatform links
Supplement mm-wave band for backhaul traffic
Introduction(2)
Introduction(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 sitedeversity
Introduction(4)
Technical benefits of optical free-space

Low-weight
 Power impact
 High data rate
 Do not interfere with RF-transmmision
OIPL(Optical inter-platform-links)
1)Downlink experiment – test, evaluation
2)Two airships – further
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)
Stratospheric Trials

FELT (Free-Space Experimental Leaser Terminal)
 Ascending 2 hours to an altitude of 22Km, staying there 8 hours while it
drift of horizontally to max 60Km imposing a link distance of up to 64Km.
Test Scenario(3)
Atmospheric Attenuation and Index-of-Refraction Turbulence

Atmospheric absorption and scattering along the link path
 Atmospheric attenuation can be kept below 2dB
 Molecular absorption lines of water vapour
IRT (Index-of-refraction turbulence)

Caused by inhomogeneous distribution of the temperature
 Coherence of an optical field has dropped
 Imposing severe problems in terms of fading and heterodyning quality for
data receiver
Description of FELT(1)
FELT consists of motorised periscope for beam setting
Description of FELT(2)
Optical Layout





Wavelength are 808nm as beacon from the optical ground station
9xx nm as beacon from the FELT
1550nm as carrier frequency for the IM/DD binary data stream
1550nm and 986nm ate combined
97x nm beacon source are also placed in the TX-path of the terminal
OGS-beacon is detected and tracked by the tracking sensor
Description of FELT(3)
PAT-processor
PAT(Pointing, Acquisition, and Tracking)

Based on CMOS imaging sensor
 Video signal is processed by an Integrated vision system
Description of FELT(4)
Communication Sub-System

3 data source at different data rates(1.25Gbps, 270Mbps, 10Mbps)
 Available modulation onto the 1550nm data signal laser diode
 The different data rates shall enable the adoption to changing weather
situations with high atmospheric attenuation during the test flight
Ground Station and Channel Measurement devices
Ground Station Setup and Data Path

Receiver system with 40cm aperture diameter is developed.
Channel Measurement Devices

Character by statistical parameter
 Disturbances of intensity distribution (size and strength of variations of the
spackle patterns)
 Optical wave-front distortions
 MASS-profiler(Multi Aperture Scintillation Sensor)
 DIMM(Differential Image Motion Monitor)
Wavelength Selection and Terminal Architecture(4)