Contents

What is HALO ?The System Architecture HALO Network conceptsAdvantages over satellite and terrestrial networks Power system and system requirementsDesirable FeaturesApplication

What is HALO ?

The High Altitude Long Operation NetworkTM is a broadband wireless metropolitan area network, with a star topology.

High Altitude Aeronautical Platform Station (HAAPS) is the technology used here.

The HALO network will be located in the atmosphere, at an altitude miles above terrestrial wireless, but hundreds to thousands of miles below satellite networks.

HAAPS means a solar powered unmanned airship capable of long endurance-may be of several years.

System architecture

HALO Aircrafts contains network elements including an ATM switch, spot beam antennas, and multibeam antennas, as well as transmitting and receiving electronics.

The antenna array provides cellular-like coverage of a large metropolitan area.

The HALO network can be connected to non-HALO networks, such as ATM networks, Internet, and frame relay via an HG/interworking unit (IWU).

Types of HAAPS

Lighter than air HAAPS are kept stationary. They are probably air balloons floating in air.

Other type is Airplane based HAAPS which are flown in a tight circle.

For broadcast application a simple antenna beams signals to terminals on the ground.

HALO Network concepts

HALO Aircraft present a new layer in the hierarchy of wireless communication - a 10 mile tall tower in stratosphere.

It is in a level above rain shower and below meteor shower.

HALO Network plane is the central node of the broad band communication.

The capacity is in the range of 10-100 Gb/s.

Elements of HALO Network

A MMW antenna array and its related components will be located in a pod suspended below air craft fuselage.

Antenna array will produce many beams typically more than 100.

Each beams will be separated by a fixed frequency.

Advantages

Over satellite network

Satellite network have expensive high power user terminal and long propagation delay.

system capacity is practically fixed.

Establishing a new satellite is very expensive.

Advantages

Over Terrestrial network

Terrestrial networks have low look angles and complex infrastructure.

They require many base stations that must be interlinked with cables.

Power system and system requirements

Aircrafts power system consist of photovoltaic cell and a regenerative fuel cell.

Advantage of using this is that it eliminates the need of and compress air at high altitude.

Aircraft size increases with increasing altitude.

Aero plane properties

The HALO aircrafts will be operated in shifts from regional airport.

HALO aero plane is specially designed for carry the hub devices and they are having long lifetime.

Look angle will be greater than 20 degree.

So the network will available in a super metropolitan area(including urban, suburban and surrounding rural area).

Other properties

HALO network can interface with the local LAN connections.

It can Interface between broadband protocols like ATM and SONET.

The HALO network will provide access to the PSTN and become the backbone for internet services like world wide web.

Subscribers Network relation

Desirable Features

Seamless multimedia services.

Adaptation to end user environment.

Rapidly deployable to sites of opportunity.

Bandwidth on demand for efficient use of available spectrum .

Applications

Widely separated customers can receive same communication as in entertainment broadcasting.

We can access interactive TV and internet.

Costumers can have large coverage area in telecommunication compared to terrestrial network.

Can use as a communication techniques for remote areas.

Can use in marine communication system.

HALO Network coverage

References

J. Martin and N. Colella, "Broadband Wireless Services from High Altitude Long Operation (HALO) Aircraft," Proc. of the SPIE International Symposium on Voice, Video, and Data Communications: Broadband Engineering for Multimedia Markets, 2000.

G. Djuknic, J. Freidenfelds, et al., "Establishing Wireless Communications Services via High-Altitude Aeronautical Platforms: A Concept Whose Time Has Come?" IEEE Communications Magazine, September 2000.

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