This paper describes the characteristics of a separate confinement heterostructure laser design based on type-I InAsSbP/InAsSb multiple quantum wells (MQW). An 8x8 band k.p method was used to calculate the band structure. The optical gain of the active region containing InAsSb QW was calculated using a free carrier gain model. Other properties such as behavior of the fundamental optical TE mode and refractive index profile were also determined. These were used for simulation of the resulting device properties and to estimate the threshold modal gain and threshold current density for the InAsSb MQW laser. Suitable InAsSbP cladding layer and waveguide/barrier materials have been determined. The strain, critical thickness, band offset, optical gain, Auger coefficient and threshold current density have been calculated at various Sb contents (x). The lowest current density is found for the composition range between 0.12<x<0.16, where the estimated laser threshold current density is 1.85-1.86 kA cm(-2).