Testing Categories

AUDIO

Real-world audio testing is performed on the live carrier network to ensure the test results reflect the actual customer experience. Our goal is to identify customer-affecting issues that negatively impact the consumer experience. Audio recordings are captured on a mini-CD and included with each report.

Testing attempts to determine performance of three main audio characteristics:

1. Echo heard on the landline side of the call while the device is operated at the maximum volume level
2. Audio levels in comparison to a benchmark device
3. The effect of background noise on both the uplink and downlink audio

Some audio technology tested by the NAC includes:

Uplink Audio

This is the audio that the far-end listener hears - usually the land-line side of a conversation.

Echo

All modern digital cellular phones use voice coders to code the human voice. This causes a delay in speech transmission that can be perceived as an echo to the far-end caller.

Downlink Audio

This is the audio that the phone or accessory user hears.

Wind Noise

Phones and headsets do little good if the far-end party cannot hear the user when operating in a windy environment. The NAC tests the headset's or mobile phone's ability to minimize the effects of wind.

Duplex Performance

This is the ability to hear and understand the other party when both parties are speaking at the same time.

Buzz

GSM phones and Bluetooth headsets may sometimes introduce a 'buzz' sound into the uplink or downlink audio path. This can vary depending on the channel, frequency band, and power level at which the mobile phone or headset is operating.

Background Noise Performance

Both the uplink and downlink audio are tested and evaluated in varying degrees of background noise.

Volume Control

An accessory can often control the volume of the downlink audio. This interaction with the phone is tested to ensure customers are not negatively impacted.

ELECTRICAL

The NAC has developed many custom test programs and routines that help us efficiently test and evaluate the electrical performance of an accessory or mobile phone. Electrical testing encompasses an evaluation of the actual electrical design and assembly of a product, as well as the charging and current draw of the product.

The NAC evaluates the performance of an electronic product AND inspects the electrical construction for potential challenges to mass production. Issues that can affect or have affected the product's performance are outlined in detail.

The 'raw-data' collected during testing is presented on a mini-CD included with each test report. This data allows manufacturers' engineers to drill down to the specific issues uncovered during testing.

Examples of what the NAC looks for and tests include:

Battery Charging Profile

A phone or Bluetooth headset contains a battery that is charged with an AC charger or vehicle power adapter (VPA). The charging is controlled by software in the headset or phone. We monitor the voltage, current and battery temperature over a period of time to determine to what level the battery was charged, and how fast (or slow) the battery is charged.

Battery Capacity

Many headsets and phones talk and standby times are determined based on the rated capacity of the battery. If the actual talk and standby battery life results are inaccurate, it may be because of an incorrectly rated battery. So we compare the manufacturer's rated capacity of the battery to the actual tested capacity.

Battery Life - Talk

The manufacturer's rated talk time is compared to the measured talk time to determine the battery life of the device during conversation.
Battery life - Music Play
The manufacturer's rated music play time is compared to the measured music play time to determine the battery life of the device during music play.
Battery life - Standby
The manufacturer's rated standby time is compared to the measured standby time. The standby battery life of a Bluetooth headset is influenced by its Bluetooth phone.

Voltage Support / Current Support

A wall charger's rated voltage is compared to the measured voltage, while its rated current is compared to the measured current.

Circuit Board Construction

We evaluate the electrical construction of a device's circuit boards including wire-routing and the method in which discrete components are secured to the board. Some boards are hand-soldered and may be prone to inconsistencies in manufacturing which could lead to high return rates. Others may have poor soldering quality that may be prone to failure.

System Connector Construction

The system connector attaches to the mobile phone or headset. Since the electrical construction of this connector can vary widely across OEM and after-market manufacturers and an incorrectly wired connector can damage a phone, we evaluate both the electrical construction and soldering quality.

ENVIRONMENTAL

In putting the consumer first, the NAC invests in labs where we can replicate real-world environments, including humidity, temperature, vibration, and static discharge. Our testing profiles can help identify problems with electrical and mechanical connections between a phone and its battery or accessories.

Humidity

NAC chambers are controlled by sophisticated test software that tests a product's mechanical properties for fit and function and measures the capabilities of products in cold, hot or humid conditions.

Vibration

Vibration testing capabilities can be performed to replicate the consumer experience of traveling in a vehicle across varying terrain.

Static Discharge

The NAC can thoroughly test phones, batteries and chargers using both contact and air-discharge techniques.

MECHANICAL

When determining what product is right for them, a consumer's first impression is often controlled by a product's mechanical characteristics. The NAC evaluates how well a product is constructed - focusing on manufacturing consistency, durability and usability - to help you deliver an attractive, easy-to-use, easy-to-manufacture product with consistent and durable quality.

The NAC scrutinizes, tests, and evaluates the mechanical construction of a device, including:

1. Everything from the plastics that are used to the method of securing the device together
2. The cosmetic appearance and consistency across multiple samples
3. Drop testing and thorough re-testing occurs before a device is inspected for latent failures

High-resolution photos on a mini-CD are included with each report. This can be useful for carriers, distributers, and manufacturers to e-mail any defects to the actual manufacturer who can often be overseas.

SAFETY

Prior to a product's release, the NAC is committed to identifying problems that may impact a customer's experience - especially safety-related issues. All NAC reports have a special symbol that can be used to convey a safety-related failure. This 'Stop Sign' is used to get the attention of the accessory buyer or manufacturer when a safety-related problem is identified:

Some areas of NAC testing include:

Short Circuit Protection

Batteries, AC chargers, and vehicle power adapters (VPAs) are tested to verify that short circuit protection is supported and operates as expected.

Over-Voltage

The battery is tested to verify that over-voltage protection is present and engages at the appropriate voltage.

Charging Battery Temperature

The battery's temperature is monitored during an overnight charge to ensure the temperature does not rise to an unacceptable level.

Device Temperature

The product's temperature is monitored to make sure it does not rise to a level that may be a cause for concern.