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thousandth in minute degree of longitude and latitude), and the altitude is rounded off to a nearest integer. GPSE has a number of existing options along with added improvement from ARL to alter the GPS scenario information, such as to pause all test nodes at one particular topology or to step to a later topology specified by a step number. Usually the GPS Emulator program should be executed by a system separated from test nodes or the MANE server.

The Range Model program is used to determine byte error rate () (the probability of error of a byte in a transmitted packet) of emulated wireless network packets which are being transmitted in an emulating mobile ad hoc network environment. The determination of is based mainly on a given transmitting power, noise power, signal modulation, and free space path loss (FSPL). The model is implemented with only two signal modulations, BPSK (binary phase-shift keying) and QPSK (quadrature phase- shift keying). There is no implementation of signal modulation changes during the communication transmission. The computed will be provided to the Forwarding Engine program to determine the packet error rate (PER) by an approximation formula ( x packet length) to save computation time. But, for the implementation at ARL, the PER is computed by the formula (1-[1-BER]L) where BER is the bit error rate, and

L is the packet length in bits.

Therefore, for ARL

applications, the Range Model program will provide BER

to the Forwarding Engine program instead of improve calculation accuracy.

to

Normally,

both

the

Forwarding

Engine

program

and

the

Range called

Model program are the MANE server.

executed by a

central system

This central

system has a

connection to all of the network interfaces (which emulate

wireless

interfaces)

of

the

test

nodes.

Multiple

MANE

servers can be server interface)

connected together (through to form a cluster of nodes that

server-to- participate

within the same reads all the data server connected

MANET environment. packets received on the

The program interfaces of a

to

that

of

the

test

nodes,

forwards

the

received packets to other MANE servers, and forwards or drops the received data packets interface(s) of destination test node(s) depending computed information provided by the Range program.

either to the on the Model

The TN Packet Treatment program is executed at test nodes to control the amount of network traffic going to and from the test network interface of test node to emulate the

effects of the MAC layer. The amount of network traffic coming in and out of test nodes is limited to a constant value specified in the MANE configuration file by a RAW-CHANNEL-CAPACITY parameter. The outbound network traffic (defined as output traffic from test node applications) is regulated by blocking applications, and the inbound network traffic (defined as input traffic to test node applications) is controlled by dropping packets. The channel rate of test network interface is calculated over the interval of time specified by the RATE_LIMIT_WINDOW parameter with the minimum of 0.24 second for 1500-byte packets (corresponding to 50kbps). No delays of packet are used to control inbound

traffic.

The Terrain-Integrated Rough-Earth Model [3] is a computer software library that calculates basic median propagation loss (path loss) of radio wave over irregular earth terrain. The calculation method was developed in the early 1960s, revived, improved, and evolved into a TIREM software version for use by the Department of Defense (DoD). The DoD TIREM version is now distributed by the Defense Information Systems Agency Joint Spectrum Center for DoD users. The TIREM code was written in the FORTRAN programming language, but had a C++

programming interface. Microsoft Windows XP environment based on the

It is available for use and Red Hat Linux 9.0 DoD version.

in the based

The TIREM can be used for radio frequencies in the range of 1 through 20,000 MHz over terrain elevations which are specified by a set of discrete points between the great- circle path of the transmitting antenna and receiving antenna. The earth terrain information can be provided by

the

digital

terrain

elevation

data

(DTED).

TIREM

provides

more

accuracy

in

the

radio

propagation

model

than the FSPL model by transmitting medium (surface

taking into account the refractivity and humidity),

antenna

properties

and

geometrical

(height , environment frequency , (relative and

polarization) , permittivity,

conductivity, and terrain elevations). The calculation of path loss is also determined by the effects of free space

spreading, diffraction, atmospheri

reflection, surface wave propagation, tropospheric scatter propagation, and c absorption but not ducting phenomena,

fading, ionospheric effects, or absorption due to rain or foliage.

To effectively use TIREM for MANE, a C++ program is used to invoke TIREM to compute the path losses of radio

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