Table 1 Summary of the parameter values used in our analysis

Radius of femtocell coverage area

10 m

Carrier frequency for femtocells

1.8 GHz

Transmit signal power by macrocellular BS

1.5 kW

Maximum transmit power by an FAP

10 mW

Height of macrocellular BS

100 m

Height of an FAP

2 m

Height of an MS

2 m

First threshold value of received signal (RSSI) from an FAP (S _T0 )

−90 dBm

Second threshold value of received signal (RSSI) from an FAP (S _T1 )

−75 dBm

Bandwidth capacity of a macrocell (C)

6 Mbps

Required/allocated bandwidth for each of the QoS non-adaptive calls

64 kbps

Maximum required/allocated bandwidth for each of the QoS adaptive calls

56 kbps

Minimum required/allocated bandwidth for each of the QoS adaptive calls

28 kbps

Ratio of traffic arrivals (QoS non-adaptive calls: QoS adaptive calls)

1:1

First SNIR threshold (Γ₁)

10 dB

Second SNIR threshold (Γ₂)

12 dB

Number of deployed femtocells in a macrocell coverage area

1000

Average call duration time (1/μ) considering all calls (exponentially distributed)

120 s

Average cell dwell time (1/η _f ) for the femtocell (exponentially distributed)

360 s

Average cell dwell time (1/η _m ) for the macrocell (exponentially distributed)

240 s

Density of call arrival rate (at femtocell coverage area:at macrocell only coverage area)

20:1

Standard deviation for the lognormal shadowing loss

8 dB

Penetration loss

20 dB