OBSAI
Encyclopedia
OBSAI, which stands for "Open Base Station Architecture Initiative", is an initiative created by Hyundai
, LGE
, Nokia
, Samsung
and ZTE
in September 2002 with the aim of creating an open market for cellular base stations. The idea behind this initiative was that an open market would substantially reduce the development effort and costs traditionally associated with creating new base station product ranges.
The OBSAI family of specifications provides the architecture, function descriptions and minimum requirements for integration of a set of common modules into a base transceiver station
. It:
This approach to writing the set of compatibility specifications is intended to provide the BTS integrator with sufficient flexibility to respond to differences in access technologies, configurations, reliability, capacity, etc.
(RF) block, baseband
block, control and clocking block, and transport block. The radio frequency
module (RFM) receives signals from portable devices (via the air interface) and converts them to digital data. The baseband block processes the encoded signal and brings it back to baseband
before relaying it to the terrestrial network via the transport block. Coordination between these three functions is maintained by a control block.
The OBSAI specification seeks to meet its goal for an open market for BTS components by defining interfaces between the four blocks and external interfaces between the "whole base station" and neighboring devices. The architecture elements thus consist of the following:
Most of the industry focus today revolves around achieving lower cost RF modules and power amplifiers (PA), as these two components usually account for nearly 50 percent of the BTS cost. Consequently, OBSAI works to define reference point 3 (RP3) prior to the other reference points to promote more competitive sources in the RF module and PA market.
device is a Serialiser/Deserialiser IC. They are usually used in pair to provide PISO/SIPO functionality at high speed link endpoints. These high speed links can be optical, or electrical interfaces (LVDS, fiber).
for instance, this is achieved using an AIR interface based on the Orthogonal Frequency Division Multiple Access technology as specified in the IEEE 802.16-2004 standard.
Hyundai
Hyundai ) is a global conglomerate company, part of the Korean chaebol, that was founded in South Korea by one of the most famous businessmen in Korean history: Chung Ju-yung...
, LGE
LG Electronics
LG Electronics is a global electronics and telecommunications company headquartered in Yeouido, Seoul, South Korea. The company operates its business through five divisions: mobile communications, home entertainment, home appliance, air conditioning and business solution...
, Nokia
Nokia
Nokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
, Samsung
Samsung
The Samsung Group is a South Korean multinational conglomerate corporation headquartered in Samsung Town, Seoul, South Korea...
and ZTE
ZTE
ZTE Corporation formerly Zhongxing Telecommunication Equipment Corporation is a Chinese multinational telecommunications equipment and systems company headquartered in Shenzhen, China...
in September 2002 with the aim of creating an open market for cellular base stations. The idea behind this initiative was that an open market would substantially reduce the development effort and costs traditionally associated with creating new base station product ranges.
The OBSAI family of specifications provides the architecture, function descriptions and minimum requirements for integration of a set of common modules into a base transceiver station
Base Transceiver Station
A base transceiver station or cell site is a piece of equipment that facilitates wireless communication between user equipment and a network. UEs are devices like mobile phones , WLL phones, computers with wireless internet connectivity, WiFi and WiMAX gadgets etc...
. It:
- defines an open, standardized internal modular structure of wireless base stations.
- defines a set of standard BTS modules with specified form, fit and function such that BTS vendors can acquire and integrate modules from multiple vendors in an OEM fashion.
- defines open, standards-based internal digital interfaces between BTS modules to assure interoperability and compatibility.
- supports different access technologies such as GSM/EDGEEnhanced Data Rates for GSM EvolutionEnhanced Data rates for GSM Evolution is a digital mobile phone technology that allows improved data transmission rates as a backward-compatible extension of GSM...
, CDMA2000CDMA2000CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
, WCDMA or IEEE 802.16IEEE 802.16IEEE 802.16 is a series of Wireless Broadband standards authored by the Institute of Electrical and Electronics Engineers . The IEEE Standards Board in established a working group in 1999 to develop standards for broadband Wireless Metropolitan Area Networks...
/WIMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
.
This approach to writing the set of compatibility specifications is intended to provide the BTS integrator with sufficient flexibility to respond to differences in access technologies, configurations, reliability, capacity, etc.
BTS structure
A Base Transceiver Station (BTS) has four main blocks or logical entities: radio frequencyRadio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
(RF) block, baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
block, control and clocking block, and transport block. The radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
module (RFM) receives signals from portable devices (via the air interface) and converts them to digital data. The baseband block processes the encoded signal and brings it back to baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
before relaying it to the terrestrial network via the transport block. Coordination between these three functions is maintained by a control block.
The OBSAI specification seeks to meet its goal for an open market for BTS components by defining interfaces between the four blocks and external interfaces between the "whole base station" and neighboring devices. The architecture elements thus consist of the following:
- Functional Blocks (the four entities seen previously)
- External network interface. This defines the interface between the BTS and the operator network. Examples are: (lub) to the Radio Network ControllerRadio Network ControllerThe Radio Network Controller is a governing element in the UMTS radio access network and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility management functions and is the point where encryption is done before...
(RNC) for 3GPP3GPPThe 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
systems, R6 to the Access Services Network Gateway (centralized Gateway) or R3 to Connectivity Services Network (CSN) for IEEE 802.16IEEE 802.16IEEE 802.16 is a series of Wireless Broadband standards authored by the Institute of Electrical and Electronics Engineers . The IEEE Standards Board in established a working group in 1999 to develop standards for broadband Wireless Metropolitan Area Networks...
/WIMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
systems. - External radio interface, between the BTS and the subscriber devices. Examples are Uu or Um to the User Equipment (UEUEUe may refer to:* Ue , a digraph used in some writing systems. Its variant Ü is a letter representing a vowel in the Estonian, German, Hungarian, and Turkish alphabets, and in pinyin* Ue , letter in many Asian languages...
) for 3GPP3GPPThe 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
systems or R1 for IEEE 802.16IEEE 802.16IEEE 802.16 is a series of Wireless Broadband standards authored by the Institute of Electrical and Electronics Engineers . The IEEE Standards Board in established a working group in 1999 to develop standards for broadband Wireless Metropolitan Area Networks...
/WIMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
. - Internal interfaces between the functional blocks known as Reference Points (RP). RP1 is the interface that allows communication between the control block and the other three blocks (RP1 also specifies UDPCP - UDP based reliable communication protocol). RP2 provides a link between the transport and baseband blocks, while RP3 connects the baseband and RF entities. RP4 provides the DC power interface between the internal modules and DC power sources.
Most of the industry focus today revolves around achieving lower cost RF modules and power amplifiers (PA), as these two components usually account for nearly 50 percent of the BTS cost. Consequently, OBSAI works to define reference point 3 (RP3) prior to the other reference points to promote more competitive sources in the RF module and PA market.
SerDes
A SerDesSerDes
A Serializer/Deserializer is a pair of functional blocks commonly used in high speed communications to compensate for limited input/output. These blocks convert data between serial data and parallel interfaces in each direction...
device is a Serialiser/Deserialiser IC. They are usually used in pair to provide PISO/SIPO functionality at high speed link endpoints. These high speed links can be optical, or electrical interfaces (LVDS, fiber).
R1 interface
This is the radio interface between the Base Station and the User Equipment. In WIMAXWiMAX
WiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
for instance, this is achieved using an AIR interface based on the Orthogonal Frequency Division Multiple Access technology as specified in the IEEE 802.16-2004 standard.