AccessRunner ADSL-USB Modem Device Set Data Sheet
2. System Description
2.1 General Description
The ADSL - USB modem solution hardware connects to the host PC via USB interface. The complete chipset and system
software is provided. The OEM adds a crystal circuit, EEPROM, RAM, LEDs, and other discrete components. All software to
support a full rate and/or G.lite ADSL modem is provided. Additionally, a control panel providing connection and system
status, an installation wizard providing automatic provisioning, a serial EEPROM programming utility, and a manufacturing
test program are provided.
2.1.1 Boot ROM and Power Up Procedure
The P5200 USB Interface Controller (UIC) contains a boot loader in internal ROM. Upon power up, the P52 UIC reads the
vendor specific USB descriptor information from EEPROM, and then enumerates with the host PC. EEPROM is required so
that USB descriptor information can be supplied during the enumeration process.
2.1.2 Serial EEPROM Programming Utility
The OEM-supplied serial EEPROM is required to store the USB device, configuration, interface, and endpoint descriptors. A
DOS-based EEPROM Programming Utility is available for the OEM to use to program the serial EEPROM with USB device,
configuration, interface, and endpoint descriptors. The USB device descriptors (including Vendor ID, Product ID, Device
Release Number, Manufacturer Name, Product Name, and Serial Number) can be customized as required.
ADSL Operating Modes
Full Rate ADSL Modes
Both T1.413 and G.992.1 (G.dmt) line coding schemes are supported for downstream rates up to 8 Mbps and upstream rates
up to 1 Mbps in 32 kbps increments. User selection of mode is supported through the provided control panel, however, auto-
provisioning is supported so that the appropriate modulation is automatically selected based on what is supported by the DSL
Access Multiplexer (DSLAM) at the Central Office. When operating in one of the full rate modes, the low and high frequency
bands must be separated with a filter. This can be done with either a service provider-installed splitter (known as “splittered
ADSL”), or with the use of distributed micro-filters in line with each POTS device on the circuit (known as “splitterless full-rate
ADSL”). Both deployment models are supported.
G.lite Splitterless Mode
G.992.2 (G.lite) splitterless mode is supported for downstream rates up to 1.5 Mbps and upstream rates up to 512 kbps in 32
kbps increments. User selection of mode is supported through the provided control panel, however, auto-provisioning is
supported so that the appropriate modulation is automatically selected based on what is supported by the DSLAM at the
Central Office. When operating in splitterless mode, the low and high frequency bands do not need to be separated with a
filter, and neither a service provider installed splitter, nor distributed micro-filters are required.
G.lite mode supports power management by defining a set of power management states for the link and the use of the
Embedded Operations Channel (eoc) to coordinate between the ATU-R and ATU-C.
RFC-1483, bridged Ethernet over ATM, is supported in the LAN driver. This protocol provides LLC encapsulation for carrying
network interconnect traffic over a single ATM AAL5 Virtual Connection. LLC encapsulation is desirable when it is not
practical to have a separate VC for each carried protocol, such as with an ATM network that only supports Permanent Virtual
Circuits (PVCs). The provided NDIS 5 drivers automatically establish a “connection-less” call using the defined PVC, and
encapsulate Ethernet bridged frames.
RFC-2364, PPP over ATM, is supported in the WAN driver. Point-to-Point Protocol provides a method of transporting multi-
protocol packets over point-to-point links. Point-to-point links allow for services such as Link Control Protocol, Network-layer
Control Protocol, and authentication. The PPP over ATM standard brings these point-to-point services to the ATM network
where they are not inherently supported. The provided NDIS 5 drivers accept an empty dial string on a specific “link” or PVC
from Windows Dial-up Networking to establish a call, and encapsulate PPP frames.