Table 3 Simulation setup.

Simulation area

1000 m × 1000 m

A standard MANET simulation area, providing enough space for node mobility without excessive sparsity or congestion

Number of nodes

50, 100, 150

Chosen to test scalability, evaluating how the Sec-BIO model performs under different network densities

Mobility model

Random waypoint

A widely used model in MANET simulations, representing realistic node movement in dynamic environments

Traffic type

Constant bit rate (CBR)

Ensures consistent data flow, enabling accurate measurement of packet delivery and latency

Packet size

512 bytes

Standard packet size in NS2/NS3 simulations, balancing realism and performance

Transmission range

250 m

Chosen based on typical Wi-Fi and MANET transmission capabilities, ensuring realistic network connectivity

Simulation time

300s

Long enough to capture network behavior trends while keeping simulation time manageable

Routing protocols

AODV, E-AODV, Sec-BIO

AODV and E-AODV serve as benchmark protocols, while Sec-BIO is evaluated for performance improvement

Encryption method

ECC (Elliptic Curve Cryptography)

Selected due to lightweight encryption, providing strong security with low computational overhead

Trust evaluation method

Elephant herding optimization (EHO)

Chosen for its efficient route selection, balancing trust, energy, and congestion dynamically

Intrusion detection method

K-means clustering

Selected for its ability to classify malicious packets efficiently with low processing cost

MAC protocol

IEEE 802.11

A standard protocol for wireless MANET communication, ensuring compatibility with real-world scenarios

Propagation model

Two-ray ground model

Provides realistic signal propagation behavior in a wireless environment, improving accuracy

Node speed

0–20 m/s

Represents typical vehicular and pedestrian mobility, covering a broad range of MANET use cases