The NMSG includes our networking processors, our application processors on radio frequency products and AISG includes a microcontroller and analog and sensors products. We reported our sales consistent with the two product groups beginning this quarter. We have included our quarterly history of revenue by-product group on our website. We are looking at Q1 in more detail. Q1 was $950 million representing a sequential decrease of 6%. Sales declined by 20% compared to Q1 last year. AISG product sales in Q1 were $527 million, 4% below the fourth quarter and 15% below Q1 of last year.
Automotive sales declined both sequential and year-over-year due to slightly elevated inventory levels at some of our customers and weakness in European production. Sales in our industrial markets increased sequential but declined year-over-year due to the strong start we saw in early 2011.
NMSG revenues were $317 million in the quarter down 16% from Q4 and down 20% from last year. The primary driver of this sequential decline was seasonal weakness in our consumer business along with declines in our RF business due to elevated inventories as several networking customers our digital networking business is worst lately on a sequential basis. And year-over-year networking revenues were negatively impacted by lower demands and pockets of elevated inventory mainly in the wireless infrastructure market.
Cellular product sales were $66 million compared to $41 million in Q1 and $138 in the first quarter of last year. Other products which consists primarily of foundry sales and IP revenue, resulted in quarterly net sales of $40 million compared to $46 million in the fourth quarter from $39 million last year.Finally, sales to distribution increased 14% sequentially and were down 17% compared to Q1 last year. Recall that the first half of 2011 was quite strong in the distribution channel. Our book-to-bill ratio in the first quarter was 1.05 this compares to the fourth quarter of 0.92.