Equipment selection process
Among service providers, one of the original key market drivers for WiMAX was the strong belief that WiMAX chips would follow the same evolutionary path as WiFi. Therefore, they would eventually be built into the majority of laptops.
For service providers, the intended ubiquity of WiMAX would mean lower costs, thus less need for subsidization and a wider potential customer base. Unfortunately, the reality has been quite different. At the peak of the hype surrounding WiMAX, embedded laptops were expected by 2007 with volumes ramping up to achieve high market penetration quickly. However, the first laptops with embedded WiMAX are only now coming to the market, and in limited numbers.
Nonetheless, several device vendors have recently reported positive signs of growing WiMAX demand. Chipset supplier Sequans has announced that it shipped its millionth WiMAX chipset in June 2009, while Beceem shipped more than 1 million WiMAX terminal chips in Q3 2009 alone. On the device side, Motorola announced at the 4G World event in September 2009 that it had shipped its millionth WiMAX end-user device.
Several industry sources have also confirmed a rapid decrease in mobile WiMAX device prices. Price points as low as $50 for a USB modem have been mentioned in relation to upcoming WiMAX projects in India.
Operators evaluating WiMAX devices should form selection criteria across four key attributes:
- Performance
- Convenience
- Control
- Reliability
Each of these attributes plays a significant role in delivering important operator and end-user benefits.
Most WiMAX operators will employ a range of WiMAX devices with varying features, functionality and price
points to attract targeted customer segments. Whether the operator is looking at top-tier devices for advanced
users or value-based devices for more basic application – it is critical that the operator selects devices that
acceptably deliver these four attributes.
While the cost of an individual WiMAX device is an important concern during the operator’s investment
decision, the operator should not be too quick to compromise cost for capability. The operator must avoid
the risk of introducing a device that is by its own measure inexpensive but contributes to a cost of network
ownership that is much higher due to the device’s limitations.
While devices optimized to address these four attributes will deliver a strong business case for the operator and
a positive experience for the end-user – devices that compromise on these attributes can quickly compromise
the health of the overall WiMAX system, increase the cost of ownership for the operator, and lead to an
unsatisfactory end-user experience.
Performance
High performing WiMAX devices not only improve the connections that individual end-user receives, but also
improve the utilization of system resources, improve the overall system capacity, and reduce the number of
supporting sites in a coverage area. Well designed devices provide significant benefit to both the end-user
experience and the operator’s economics.
Key performance parameters to evaluate when considering WiMAX devices include receiver sensitivity,
antenna gain, diversity gain, and orientation loss.
Devices in the market have demonstrated up to 1dB of variance across these performance parameters.
Operators should evaluate the device performance balanced with the device cost and, most importantly, the
impact to the total cost of ownership of the WiMAX network.
Device Receiver Sensitivity
A key specification for any radio is the receiver sensitivity. Receiver sensitivity for a WiMAX device is a
measurement of how faint the radio signal from the base station may go while still being successfully received
by the device. Higher receive sensitivity offers the following system wide advantages:
» Larger coverage radius for a cell site
» Larger area served by higher order modulation within cell radius
» Fewer base sites required within the service perimeter
» Higher end-user effective throughput
» Greater tolerance for deep indoor penetration
The WiMAX Forum specifies the receiver sensitivity requirements for each certification profile at each of the
varying modulation schemes. While this offers a minimum, baseline target for manufacturers to design to;
well designed RF components within the WiMAX devices should be able to deliver as much as 5 dB higher
receiver sensitivity than the WiMAX Forum requirements or more than three times higher. With this improved
sensitivity, an operator can effectively double the area covered by the higher order modulation schemes,
increasing throughput and optimizing system resources as well as reducing the number of sites by almost
50% in the coverage area.
Given the tremendous advantage improved receiver sensitivity can offer, WiMAX operators would be well
advised to consider this measurement as a key selection criteria for their devices.
Device Isolation for Wi-Fi & WiMAX
Many full-featured WiMAX devices are looking to integrate Wi-Fi capability into the device. WiMAX can be used
to provide the broadband backhaul to the premises and the integrated Wi-Fi can be used to additionally support
local area distribution of the broadband signal and connect to a broader array of Wi-Fi enabled devices.
A large percentage of global WiMAX installations are focused on employing the 2.5 GHz band. Recognizing that
Wi-Fi operates largely in the nearby 2.4 GHz band, operators seeking to deploy WiMAX at 2.5 GHz must ensure
that their devices provide ample isolation between the WiMAX and Wi-Fi radios. Merely integrating the two
radios into a device can result in significant interference, increasing the number of WiMAX re-transmissions
due to packet loss, requiring greater system resources to support the connection, and ultimately degrading
the end-user throughput – despite receiving a strong WiMAX signal strength at the receiver.
Operators should ensure that selected WiMAX devices with integrated Wi-Fi capability employ innovative
RF design considering techniques such as switched, diversity antennas and high-performing RF components
which will offer high WiMAX and Wi-Fi isolation. Such devices increase the effective throughput for the
end-user and minimize impact to overall system capacity by reducing resource intensive error correction and
scheduler processing.
Antenna Gain, Diversity Gain, & Orientation Loss
High performing WiMAX devices should demonstrate strong antenna gains employing the full benefit of the
diversity techniques allowed with multi-antenna designs. While certified WiMAX devices must support MIMO
capabilities as specified in the certification profiles, better devices will also incorporate additional techniques
such as Maximal-Ratio Combining (MRC) to combine the multiple signals for more robust reception. This
represents a basic capability of sound RF design and a fundamental measurement for device comparison.
Additionally, the devices should offer minimal orientation loss, offering the end-user greater freedom for where
in the premise the device is positioned and in what orientation. WiMAX devices will find their place in such
likely environments as the living room or media center. Stylish design may find its value diminished if the end-user has to investigate and discover optimal placement for acceptable signal reception.
Convenience
The end user’s WiMAX experience begins at the point where they carefully select and purchase their WiMAX
device and bring it home. Stylish designs will help motivate their selection; however, the greater test of the
experience takes place once the user plugs in the device and attempts to activate their service. When an
end-user activates his device for the first time, he should seamlessly achieve an easy, broadband connection.
Just as important, every following time he logs on to the service he should experience a reliable, speedy
authentication. This type of satisfying end-user experience will contribute to customer loyalty over the long-term.
Speed Entry to WiMAX Service
Preferred WiMAX device solutions should be paired with support for seamless system integration of these
devices into the operator’s provisioning and service delivery platforms to eliminate the degree of intervention
required from the end-user and speed their entry onto the WiMAX service.
Many WiMAX operators’ device distribution processes allow for an inventory of pre-provisioned devices to
be sold through retail channels as well as approved devices that may be optionally added to the provisioning
system after service activation.
Pre-Provisioned Devices “Plug and Play”
With a pre-provisioned device, once the end-user is approved and the device is brought home, the device can
be merely powered up and connected to a computer to have the WiMAX service engaged. This represents
a true Plug and Play experience. As more computer accessories and peripherals move to Plug and Play
interfacing, this is becoming an expectation of the end-user and anything otherwise will fall short.
The time it takes to activate service upon first power-up can vary depending on the capability of the device
and its integration into the provisioning system. The industry’s best solutions have demonstrated less than 40
seconds to service activation in comparison to alternative solutions that may take many times longer.
Approved, but Not Pre-Provisioned
For approved devices that have not been pre-provisioned, the end-user should also be supported with a speedy
process for service activation. Leading device vendors have demonstrated systems and operational support
to engage a straightforward process for such activations. Once the device is powered up, the end-user has
to only select from a menu of available WiMAX service providers, provide personal and billing information,
and offer the unique device ID printed on the package. The operator’s role in activating the service should be
fully automated and supported through over-the-air provisioning significantly reducing the operational cost of
activating a subscriber.
Steps for Activating an Approved WiMAX Device onto a WiMAX Network
1. End user purchases an approved, non-provisioned device from a retail channel
2. Upon powering for the first time, the device will perform a band scan across all available RF channels to
determine what WiMAX service providers are available.
3. Similar to enabling a Wi-Fi device, a list of available WiMAX service providers will be announced and the end-user has the opportunity to select the provider of choice.
4. The connection is immediately re-directed to the operator’s service provisioning landing page where key
vitals of the end-user are collected including profile information, billing details, and subscription preferences.
5. The operator will request the end-user to enter their unique device ID printed conveniently within the
package and on the device. The device ID is typically a combination of the MAC address and the serial
number of the device.
6. The operator will validate the information and upon election to grant service, the system will provision the
user device onto the AAA and Home Agent (HA).
7. The end-user is authenticated, security keys are exchanged, and the broadband connection is enabled.
Eliminate the Need to Load Drivers
The need to install drivers and configure the computer to acknowledge the WiMAX device can be a burdensome
process, especially when the end user is eager to engage in the WiMAX experience. Selecting a WiMAX
device that has all necessary software drivers pre-loaded, utilizes standard Ethernet interfacing to connect
to the computer, and places no requirement on the computer’s operating system can substantially ease the
end-user’s path to connectivity.
Operators will benefit by selecting device vendors who are capable of extending their solution to consider
how the device integrates into the broader WiMAX system. Such an integrated solution will offer great
advantage to the convenience of the service – both for the operator and the end-user.
Control
Operators must have full control and management over their network, the established base of devices operating
on that network, and the service delivered to the end user. Centralized device management supporting
remote management and administration and health monitoring is a critical capability for enabling such control.
Additionally, it is important that operators consider devices supporting standardized management protocols
to allow their WiMAX devices to fit into a common platform managing the entirety of their devices portfolio
irrespective of device type or technology.
Centralized Device Management
The Device Management Platform should provide a single, centralized control point for managing the entire
base of subscriber devices including remote management and administration and health monitoring. The
platform will integrate into the operator’s Customer Relationship Management (CRM) system and play a key
role throughout the service lifecycle from activation, routine maintenance, trouble ticket issuance, incident
resolution, and service termination. Additionally, the platform will support administration and enforcement of
the business rules associated with the various service types.
Key device management features
» Over-the-air, remote management and software updates to subscriber devices
» Policy-based auto-configuration, monitoring and debugging of devices
» Fault management and status queries from the device
» Enforcement of varying service tiers and service priorities
» Administration of subscription models such as pre-pay or wholesale arrangements
» Extended configuration and management capability for devices bridged by the WiMAX device and resident
in the downstream local network
Remote Management & Administration
As subscribership grows on the WiMAX network, the need for highly capable remote management and
administration capabilities becomes paramount for the operator. The operator’s WiMAX system connecting
from the central management to the device must support no-touch, over-the-air provisioning, configuration,
and software upgrades. This capability will offer the operator the assurance of full management control over
the system, the ability to reduce operational costs associated with system upgrades or configuration changes
– and more importantly, the opportunity to rapidly grow their subscriber base without operational overhead.
Health Monitoring
Operators will want to ensure that the devices they select integrate with the management systems to deliver
as much real-time information as possible regarding the health and performance of their devices deployed
throughout the network. The more information that is available the greater intelligence the operator will have
regarding how the network is being utilized, what opportunities exist to optimize the service, and resolving
issues immediately as they arise.
Should an end-user have an issue with their service or their device, having such real-time data empowers
the customer care professionals to conduct more detailed troubleshooting, increase the resolution rate, and
decrease the number of service visits. Ultimately, this will improve the customer’s satisfaction with their
service and save the operator significant operating costs.
Standards-Based Device Management
WiMAX is blending the environments of traditional cellular service and traditional wireline broadband by offering
wireless, mobile broadband connections. With the marriage of these environments we are seeing whole new
families of end-user devices emerge that integrate the capabilities found in both cellular and wired broadband
devices. An operator’s WiMAX device portfolio is likely to include desktop modems, mobile Internet devices,
PC adaptors, ultra-mobile computers, and an assortment of consumer electronics.
Additionally, a WiMAX operator may already have existing cellular or wireline assets with a large base of
associated, established devices including mobile devices, set top boxes, broadband modems, and media
gateways.
Operators will want the efficiencies of managing the entirety of their devices portfolio irrespective of device
type or technology. This requires utilizing standards based device management protocols that can be integrated
into a common device management platform.
WiMAX device manufacturers will need to support industry leading device management standards to offer all
operators the opportunity to effectively control their device population without adding unnecessary systems
complexity and cost overhead.
Two principal standardized device management protocols are administered in the industry today:
» OMA-DM - Open Mobile Alliance Device Management
» TR-09 - DSL Forum Technical Report 09
Deploying WiMAX devices that are conformant to both OMA-DM and TR-09 will offer operators the greatest
flexibility in managing a broad array of subscriber devices. With such devices, operators will benefit from
» Standard interfaces allowing the device to be deployed easily on any manufacturer’s WiMAX network
» A single management platform addressing all manner of devices from mobile devices to desktop
modems
» Interoperability with a wide variety of commercial, off-the-shelf management platforms
Industry standard device management protocols
OMA-DM
Wireless Devices
The OMA-SM device management protocol has been specified through the Open Mo-bile Alliance and was developed to support the management of such devices as mobile phones and PDAs. The specification is tailored to smaller devices where memory or
storage may be limited.
TR-069
Wireline Devices
The TR-069 device management protocol has been specified through the DSL Forum and provides support to modems, routers, gateways, set top boxes, and VoIP phones and adapters.
Advanced Security Features
The WiMAX technology standard specified by IEEE maintains powerful standards-based security controls.
These controls include the PKMv2 EAP-based standard between the device and the radio access network,
over-the-air AES-based (Advanced Encryption Standard) encryption for subscriber traffic and AAA protocols
for device authentication.
However, security planning for an operator’s WiMAX network must extend beyond the security protocols
inherent in the technology. Operators need to ensure that deployment efforts address and prioritize WiMAX
security initiatives and that their design and integration adds a number of key security best practices into
existing operational processes and policies. Managing security from the onset of deployment is an important
step in managing the ongoing operational expense of running a healthy WiMAX service.
WiMAX devices play a key role in securing the WiMAX service. Leading WiMAX device vendors go beyond
the IEEE security specifications to further secure the network through capabilities such as built in firewalls
– inspecting and regulating network traffic as it travels over the WiMAX connection and denying or permitting
the passage based on prescribed business rules.
Quality of Service (QoS)
WiMAX systems must be capable of administering an end-to-end QoS framework to meet the needs of true
carrier-class deployments.
Leading WiMAX solutions should be capable of provisioning each end-user with a set of service flows mapping
to the various services offered by the operator. For example, VoIP and data services may be defined as two
distinct service flows for an end-user. Both service flows could be associated with appropriate QoS related
parameters.
These parameters must be monitored and managed at multiple points across the network including the device
to provide proper handling of the end-to-end service. Leading WiMAX devices should support the five classes
of QoS (UGS, rtPS, ertPS, nrtPS, and BE) as defined by the IEEE 02.1e specification. The broad support of
the varied scheduling classes enables a range of services including robust voice and data management and
service level assurance.
Reliability
Device reliability can have a profound impact on the both the end-user’s experience as well as on the operator’s
financials. Device reliability has been demonstrated to have direct correlation to the degree of inventory
required for device replacement, the load on customer care and resolution resources, customer satisfaction
ratings, and customer churn. Operators must be certain that their selected WiMAX devices are supported by
high quality manufacturing processes and rigorous testing and acceptance criteria
High Quality Manufacturing Processes
WiMAX devices must adhere to recognized and established quality processes during manufacturing to ensure
the highest reliability devices with limited defects and failure rates.
Different countries may have specific requirements for validation of manufacturing processes. ISO
(International Organization for Standardization) certification is typically an important validation criterion.
ISO is an international standard-setting body composed of representatives from various national standards
organizations. The organization specifies conformance testing standards for WiMAX devices required in many
regions.
Leading WiMAX device vendors will employ best in class quality processes including Six Sigma and Capability
Maturity Model Integration (CMMI). Six Sigma is a set of quality practices originally developed by Motorola to
systematically improve the business processes for predictable, defect-free performance. CMMI is a process
improvement methodology that can optimize the product development and supply chain management
processes.
Rigorous Testing and Acceptance Criteria
Leading WiMAX vendors must conduct rigorous testing of its device population to ensure expected
performance once the device enters the field. WiMAX Forum® certification is an important way for vendors
to build confidence in device interoperability and conformance to key performance specifications. Certification
offers operators a greater level of assurance that their investments can deliver reliable and flexible solutions.
However, certification, as important as it is, cannot be considered the final step in interoperable WiMAX
solutions. To design and deploy a successful WiMAX network, each operator must choose vendor partners
who are prepared to continue testing, proving and integrating certified equipment in real-world, multi-vendor
environments.
To be successful in its respective market, each WiMAX network deployment will require customized features
that go beyond the scope of certification. Each requires additional testing and verification in controlled
environments, as well as further proving in a First Office Application (FOA) where devices, base stations and
other elements unique to the particular network are methodically integrated and verified. Operators should
select WiMAX devices from vendors that have undergone such rigorous testing with proof points from the
laboratory as well as from the field.