Mini PCI is a standard for a computer bus for attaching peripheral devices to a computer motherboard and is an adaptation of the Peripheral Component Interconnect (PCI) bus. It was designed for laptops and other small-footprint computer systems.

There are three card form factors: Type I, Type II, and Type III cards. The card connector used for each type include: Type I and II use a 100-pin stacking connector, while Type III uses a 124-pin edge connector, i.e. the connector for Types I and II differs from that for Type III, where the connector is on the edge of a card, like with a SO-DIMM. The additional 24 pins provide the extra signals required to route I/O back through the system connector (audio, AC-Link, LAN, phone-line interface). Type II cards have RJ11 and RJ45 mounted connectors. These cards must be located at the edge of the computer or docking station so that the RJ11 and RJ45 ports can be mounted for external access.

Type Connector Size
IA 100-Pin Stacking 7.5 × 70 × 45 mm
IB 100-Pin Stacking 5.5 × 70 × 45 mm
IIA 100-Pin Stacking 7.5 × 70 × 45 mm
IIB 100-Pin Stacking 17.44 × 78 × 45 mm
IIIA 124-Pin Card Edge 2.4 × 59.6 × 50.95 mm
IIIB 124-Pin Card Edge 2.4 × 59.6 × 44.6 mm

There are following mini pci 802.11 cards:
802.11b  11M
802.11b/56k modem combo card, 11M
802.11b/g 54M, 108M(atheros)
802.11a/b/g 54M, 108M9(atheros)
802.11/modem/bluetooth  ONLY work on special laptops(bluetooth chipset is on motherboard, NOT mini pci card)

PCI Express Mini Card

The PCI Express Mini Card replaces the Mini PCI card, which is a small internal card functionally identical to standard desktop computer PCI cards. Mini PCI cards are used mainly to add communications functions to portable computers that are built- or customized-to-order. The PCI Express Mini Card is half the size of the Mini PCI card as shown in Figure 9. This allows system designers to include one or two cards, depending on the size constraints of a particular portable computer.

intel  3945ABG  802.11a/b/g 54M
intel 4965AGN 802.11N 300M
intel 4965AG 802.11a/g 54M

Atheros 5008 802.11N 300M
Atheros 5424 802.11a/b/g 54m

Broadcom 4311 802.11a/b/g or 802.11b/g 54M
Broadcom 4321 802.11N 300M
   
802.11N: Draft N.