Table 3 Definition of notations

R _m

Macrocell transmission radius

R _f

Femtocell transmission radius

P ^R

Desired received signal strength at UE

α

Path loss exponent

K _t

Set of femtocells

K _s

Set of femtocells with shared spectrum

K _p

Set of femtocells with partitioned spectrum

ν _s

Ratio of shared spectrum

ν _p = (1 - ν _s )

Ratio of partitioned spectrum

N _b

Number of beams

g _m

Beamforming gain for the main lobe

g _s

Beamforming gain for the side lobe

γ _m

Measured SIR at MUE

γ _f

Measured SIR at HUE

${\gamma }_m^q$

Required SIR at MUE

${\gamma }_f^q$

Required SIR at HUE

F ₁

Set of HeNBs whose associated HUE has a SIR greater than ${\gamma }_f^q$

$S_{{\mathbf{F}}_{\mathbf{1}}}$

Interference at MUE from HeNBs in F ₁

S _m

Interference at MUE with the HeNB selection policy

$S_m^q$

Permitted interference at MUE for ${\gamma }_m^q$

p _s

Probability to use full spectrum

$p_s^E$

p _s of the equal selection policy

$p_s^W$

p _s of the interference weighted selection policy