LTE-Advanced carrier aggregation

Modes of carrier aggregation

3GPP, short for 3rd Generation Partnership Project and the standardization body behind LTE, is addressing IMT-Advanced requirements by standardizing LTE-Advanced as part of its Release 10.

LTE-Advanced comprises a set of features, while one of the most demanded feature is carrier aggregation (CA). LTE-Advanced allows the aggregation of at a maximum five component carriers up to 20 MHz of bandwidth to attain a total transmission bandwidth of up to 100 MHz. As none of the service providers owns continuous spectrum of 100 MHz three different modes of carrier aggregation exist: intra-band contiguous and non-contiguous as well as inter-band carrier aggregation. 3GPP’s RAN Working Group 4 (RAN4), responsible for setting performance requirements, initially limits the aggregation to two component carriers only.

The signaling towards an end user device for carrier aggregation affects only certain layers, not the entire protocol stack. For instance, the device is permanently connected via its PCC to the serving Primary Cell (PCell). Non-Access Stratum (NAS) functionality such as security key exchange and mobility information are provided by the PCell. All secondary component carriers are understood as additional transmission resources. For the Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) layer carrier aggregation signaling is transparent. A terminal is configured on the Radio Resource Control (RRC) layer, to handle secondary component carriers. Moreover, on RRC the parameters of the SCell(s) are configured. The Medium Access Control (MAC) layer acts as multiplexing entity for the aggregated component carriers as they are activated or deactivated by MAC control elements. In case of activation in subframe n, than 8 subframes (8 ms) later the resources are available to the device and it can check for scheduling assignments. While the MAC acts as multiplexer, note that each component carrier has its own Physical Layer (PHY) entity, providing channel coding, HARQ, data modulation and resource mapping.

Carrier aggregation is one key enabler of LTE-Advanced to meet the IMT-Advanced requirements in terms of peak data rates. It is a highly demanded feature from a network operator perspective, since it enables also the aggregation of different spectrum fragments. However, the major design challenge is on terminal side. Support of higher bandwidths and aggregation of carriers in different frequency bands increase complexity of transceiver circuits, including component design like wideband power amplifiers, highly efficient switches and tunable antenna elements. Further the additional functionality provided to PHY/MAC layer and the adaptations to the RRC layer need to be thoroughly tested. Rohde & Schwarz offers a multitude of solutions for testing LTE-Advanced carrier aggregation implementations. The broad offering includes signal generators and analyzers for performing physical layer tests on base stations, mobile devices or components as well as base station emulators for physical layer and protocol tests for all kind of wireless devices and chipsets.

Contact us for more information

Related products

R&S®CMW500 wideband radio communication tester

Universal tester for air interface testing including LTE-A PHY testing and full protocol stack testing incl. support of MLAPI layer 3 test scenarios

Product information

R&S®SMW200A vector signal generator

Unique one-box solution for carrier aggregation with integrated realtime fading for 2x2 MIMO receiver tests

Product information

R&S®FSW signal and spectrum analyzer

The multistandard radio analyzer function (MSRA) simultaneously measures signals on multiple LTE carrier frequencies and/or on different standards (GSM, WCDMA, LTE, etc.).

Product information

R&S®TSMx drive and walk test scanner

Ideal tool for LTE-Advanced carrier aggregation measurements: two independent RF and signal processing paths, each with a bandwidth of up to 20 MHz

Product information

R&S®ROMES4 drive test software

One software that covers all main technologies; ideal for network optimization for LTE-Advanced carrier aggregation

Product information

Related resources

Get your free LTE-A Pro white paper

Get insights about the LTE-Advanced Pro enhancements in 3GPP Releases 13 and 14 that address the mobile broadband use case.

Register now

App note: Testing LTE-A Releases 11 and 12

Test solutions for LTE-Advanced Releases 11 and 12 enhancements for carrier aggregation.

More information

LTE-A Pro: 8 CA DL / 4 CA UL testing

LTE-A Pro: 8 CA DL / 4 CA UL testing presented at GSMA MWC 2018

Rohde & Schwarz demonstrated LTE-A Pro user equipment testing with enhanced carrier aggregation (eCA) from 3GPP Rel. 13 at the GSMA Mobile World Congress 2018 in Barcelona.

Carrier Aggregation – (One) Key Enabler for LTE-Advanced

Webinar: Carrier aggregation – (One) key enabler for LTE-Advanced

This webinar focuses on carrier aggregation, the most demanded feature in LTE-Advanced.

Related topics

LTE testing

More information

5G NR testing

More information

Wireless communications testing

More information

Request information

Do you have questions or need additional information? Simply fill out this form and we will get right back to you.

I want to receive information from Rohde & Schwarz via

Marketing permission

What does this mean in detail?

I agree that Rohde & Schwarz GmbH & Co. KG and the Rohde & Schwarz entity or subsidiary company mentioned in the imprint of this website, may contact me via the chosen channel (email or postal mail) for marketing and advertising purposes (e.g. information on special offers and discount promotions) related to, but not limited to, products and solutions in the fields of test and measurement, secure communications, monitoring and network testing, broadcast and media, and cybersecurity.

Your rights

This declaration of consent may be withdrawn at any time by sending an email with the subject "Unsubscribe" to news@rohde-schwarz.com. Additionally, a link to unsubscribe from future email advertisements is contained in each email sent. Further details on the use of personal data and the withdrawal procedure are set out in the Statement of Privacy.

Your request has been sent successfully. We will contact you shortly.
An error is occurred, please try it again later.